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Objective This prospective study assessed the risk of developing rotator cuff syndrome (RCS) with separate or specific combinations of biomechanical exposures measures, controlling for individual confounders. Background Compared with other musculoskeletal disorders, rates of work-related shoulder musculoskeletal disorders have been declining more slowly. Method We conducted up to 2 years of individual, annual assessments of covariates, exposures, and health outcomes for 393 U.S. manufacturing and healthcare workers without RCS at baseline. Task-level biomechanical exposures assessed exposure to forceful exertions (level, exertion rates, duty cycles), vibration, and upper arm postures (flexion, abduction). Hazard ratios (HRs) were calculated with Cox proportional hazard models. Results We observed 39 incident RCS cases in 694 person-years (incidence rate = 5.62 per 100 person-years). Adjusting for confounders, we found increased risk of incident RCS associated with forceful hand exertions per minute for three upper arm posture tertiles: flexion ≥45° (≥28.2% time, HR = 1.11, CI [1.01, 1.22]), abduction ≥30° (11.9–21.2%-time, HR = 1.18, CI [1.04, 1.34]), and abduction >60° (≥4.8% time, HR = 1.16, CI [1.04, 1.29]). We failed to observe statistically significant effects for other interactions or any separate measures of biomechanical exposure. Conclusion This study highlights the importance of assessing combinations of exposure to forceful repetition and upper arm elevation when developing interventions for preventing RCS. Application Based on these results, interventions that reduce exposure to forceful repetition (i.e., lower force levels and/or slower exertion rates) may reduce the risk of RCS, especially when upper arm elevation cannot be avoided.

Objective To update trends in prevalence of back and upper limb musculoskeletal symptoms and risk factors from the 2014 Quality of Work Life (QWL) Survey. Methods Quadrennial QWL Surveys, 2002-2014 (with N = 1455, 1537, 1019, and 1124 in 2002, 2006, 2010, and 2014 surveys respectively) were analyzed for reports of back pain and pain in arms. Results In the fourth analysis of this survey, twelve-year trends continue to show a decline in back pain and pain in arms. Key physical (heavy lifting, hand movements, very hard physical effort) and psychosocial/work organizational factors (low supervisor support, work is always stressful, not enough time to get work done) remain associated with back and arm pain, with the physical risk factors showing the strongest associations. Conclusion Physical exposure risk factors continue to be strongly associated with low back and arm pain and should be the focus of intervention strategies.

OBJECTIVE: To examine the auditory system of Brazilian gasoline station workers using an extensive audiological test battery. DESIGN: This was a cross-sectional study. The audiological evaluation included a questionnaire, pure-tone audiometry, acoustic immittance tests, transient-evoked otoacoustic emissions (TEOAEs), distortion product otoacoustic emissions (DPOAEs), auditory brainstem response (ABR), and P300 auditory evoked potentials. STUDY SAMPLE: A total of 77 Brazilian gasoline station workers were evaluated, and their results were compared with those of 36 participants who were not exposed to chemicals or noise at work. The gasoline station employees worked in 18 different gas stations, and the noise area measurements from all gas stations revealed time-weighted averages below 85 dBA. RESULTS: Of the 77 gasoline station workers evaluated, 67.5% had audiometric results within the normal range, but 59.7% reported difficulties in communication in noisy places. Gasoline station workers showed significantly poorer results than non-exposed control participants in one or more conditions of each of the audiological tests used, except P300. CONCLUSIONS: The results suggest that the gasoline station workers have both peripheral and central auditory dysfunctions that could be partly explained by their exposure to gasoline.

Regression analysis was used to estimate and test for relationships between the blood lead concentration and the concentrations of serum thyroid stimulating hormone and serum total thyroxine in adults, 20 years and older, participating in the third National Health and Nutrition Examination Survey. No relationship was found between the blood lead level and the concentration of serum thyroid stimulating hormone. The serum total thyroxine concentration decreased as the blood lead level increased in women, but not in men. The lowest concentration of blood lead at which a relationship could be detected was 2.1 μg/dL and 3.9 μg/dL for the non-pregnant and pregnant women, respectively. Hypothetical mechanisms of the action of lead are discussed.

OBJECTIVES: In order to produce near real-time onsite results to detect surface contamination by antineoplastic drugs, the National Institute for Occupational Safety and Health developed monitors for 5-fluorouracil, which use surface wiping and lateral flow immunoassay for measurement. The monitors were tested in the laboratory to assess the sensitivity of detection on laboratory-produced contaminated surfaces. A field evaluation to assess the capability of the monitors to make measurements in healthcare workplaces was carried out in collaboration with a medical device company and the results are presented in this report. METHODS: The 5-fluorouracil monitor was evaluated in areas where oncology drugs were prepared and administered to patients at five different hospitals. The levels of contamination measured with the monitors were compared to levels measured with liquid chromatography-tandem mass spectrometry. RESULTS: The 5-fluorouracil values measured with the liquid chromatography-tandem mass spectrometry ranged from 0 to over 200,000 ng/100 cm(2). Measurements by the 5-fluorouracil monitors in the range 10–100 ng/100 cm(2) correlated with the liquid chromatography-tandem mass spectrometry. Receiver operating characteristic curves developed for the data indicated that a positive limit of 22 ng/100 cm(2) would give an acceptable level of false-positives while retaining most true-positive samples. If the liquid chromatography-tandem mass spectrometry measured greater than 100 ng/100 cm(2), then the monitors also measured levels greater than 100 ng/100 cm(2) for the majority of samples. CONCLUSION: The data indicate that there are many areas in hospitals that are contaminated with 5-fluorouracil and the monitors will be useful in identifying this contamination.

The National Institute for Occupational Safety and Health (NIOSH) sponsored tests of three earplug fit-test systems (NIOSH HPD Well-Fit™, Michael & Associates FitCheck, and Honeywell Safety Products VeriPRO®). Each system was compared to laboratory-based real-ear attenuation at threshold (REAT) measurements in a sound field according to ANSI/ASA S12.6-2008 at the NIOSH, Honeywell Safety Products, and Michael & Associates testing laboratories. An identical study was conducted independently at the U.S. Army Aeromedical Research Laboratory (USAARL), which provided their data for inclusion in this report. The Howard Leight Airsoft premolded earplug was tested with twenty subjects at each of the four participating laboratories. The occluded fit of the earplug was maintained during testing with a soundfield-based laboratory REAT system as well as all three headphone-based fit-test systems. The Michael & Associates lab had highest average A-weighted attenuations and smallest standard deviations. The NIOSH lab had the lowest average attenuations and the largest standard deviations. Differences in octave-band attenuations between each fit-test system and the American National Standards Institute (ANSI) sound field method were calculated (Attenfit-test - AttenANSI). A-weighted attenuations measured with FitCheck and HPD Well-Fit systems demonstrated approximately ±2 dB agreement with the ANSI sound field method, but A-weighted attenuations measured with the VeriPRO system underestimated the ANSI laboratory attenuations. For each of the fit-test systems, the average A-weighted attenuation across the four laboratories was not significantly greater than the average of the ANSI sound field method. Standard deviations for residual attenuation differences were about ±2 dB for FitCheck and HPD Well-Fit compared to ±4 dB for VeriPRO. Individual labs exhibited a range of agreement from less than a dB to as much as 9.4 dB difference with ANSI and REAT estimates. Factors such as the experience of study participants and test administrators, and the fit-test psychometric tasks are suggested as possible contributors to the observed results.

This study was conducted at 5 Veterans Administration Medical Centers (VAMCs). A cross sectional survey was administered to 134 workers who routinely lift and mobilize patients within their workplaces' safe patient handling and mobility (SPHM) programs, which are mandated in all VAMCs. The survey was used to examine a comprehensive list of SPHM and non-SPHM variables, and their associations with self-reported musculoskeletal injury and pain. Previously unstudied variables distinguished between "bariatric" (≥300 lb or 136 kg) and "non-bariatric" (300 lb or 136 kg) patient handling. Significant findings from stepwise and logistic regression provide targets for workplace improvements, predicting: lower injury odds with more frequently having sufficient time to use equipment, higher back pain odds with more frequent bariatric handling, lower back pain odds with greater ease in following SPHM policies, and lower odds of upper extremity pain with more bariatric equipment, and with higher safety climate ratings.

Introduction Investigations of the effects of occupational exposure to lead on the concentrations of thyroid hormones in the blood have not produced consistent results. A meta-analysis was performed to assess the effect of occupational exposure to lead on thyroid hormone concentrations using the results from published studies. Methods Group means from studies of the thyroid function of persons occupationally exposed to lead were used in a meta-analysis. Differences between the control and exposed groups, and the slopes between thyroid hormone concentrations and log10 blood lead concentrations or duration of exposure to lead were estimated using mixed models. The hormones analyzed were thyroid stimulating hormone, total and free thyroxine, and total and free triiodothyronine. Results No differences in mean thyroid hormone concentrations were found between the exposed and control groups. No relationships were found between blood lead or the duration of exposure to lead and thyroid hormone concentrations. Conclusion The results of the analysis do not provide evidence for an effect of occupational lead exposure on thyroid function in men. Am. J. Ind. Med. Published 2016. This article is a U.S. Government work and is in the public domain in the USA.

Persistent organohalogens (POHs) and metals have been linked to alterations in menstrual cycle function and fertility in humans. The Cree First Nations people living near James Bay in Ontario and Quebec, Canada, have elevated levels of POHs, mercury and lead compared to other Canadians. The present study examines the interrelationships between selected POHs and elements on menstrual cycle function in these Cree women. Menstrual cycle characteristics were derived from structured daily diaries and endocrine measurements from daily urine samples collected during one cycle for 42 women age 19-42. We measured 31 POHs in blood plasma and 18 elements in whole blood, for 31 of the participants. POHs and elements detected in ≥ 70% of the participants were transformed by principal component (PC) analysis to reduce the contaminant exposure data to fewer, uncorrelated PCA variables. Multiple regression analysis revealed that, after adjusting for confounders, PC-3 values showed significant negative association with cycle length, after adjusting for confounders (p = 0.002). PC-3 accounted for 9.2% of the variance and shows positive loadings for cadmium, selenium, and PBDE congeners 47 and 153, and a negative loading for copper. Sensitivity analysis of the model to quantify likely effect sizes showed a range of menstrual cycle length from 25.3 to 28.3 days using the lower and upper 95% confidence limits of mean measured contaminant concentrations to predict cycle length. Our observations support the hypothesis that the menstrual cycle function of these women may be altered by exposure to POHs and elements from their environment.

BACKGROUND: This article examines serious and fatal pneumatic nail gun (PNG) injury investigations for workplace, tool design, and human factors relevant to causation and resulting OS&H authorities' responses in terms of citations and penalties. METHODS: The U.S. Occupational Safety and Health Administration (OSHA) database of Fatality and Catastrophe Investigation Summaries (F&CIS) were reviewed (1985-2012) to identify n = 258 PNG accidents. RESULTS: 79.8% of investigations, and 100% of fatalities, occurred in the construction industry. Between 53-71% of injuries appear to have been preventable had a safer sequential trigger tool been used. Citations and monetary penalties were related to injury severity, body part injured, disabling of safety devices, and insufficient personal protective equipment (PPE). CONCLUSIONS: Differences may exist between construction and other industries in investigators interpretations of PNG injury causation and resulting citations/penalties. Violations of PPE standards were penalized most severely, yet the preventive effect of PPE would likely have been less than that of a safer sequential trigger. Am. J. Ind. Med. Published 2015. This article is a U.S. Government work and is in the public domain in the USA. Language: en

We sought to determine the time-course in androgen and semen parameters in men after weight loss associated with bariatric surgery with a prospective cohort study of 6 male subjects, age 18-40 years, meeting NIH bariatric surgery guidelines, conducted in 2005-2008, with study visits at baseline, then 1, 3, 6 and 12 months after surgery. All men had a Roux-en-y-Gastric-Bypass (RYGB) performed at Penn State Milton S. Hershey Medical Center. We collected at each visit biometric, questionnaire, serum, and urinary specimens as well as a semen analysis. Urinary integrated total testosterone levels increased significantly by 3 months after surgery, and remained elevated throughout the study. Circulating testosterone levels were also higher at 1 and 6 months after surgery, compared to baseline. Serum SHBG levels were significantly elevated at all time points post-operatively. After RYGB surgery, there were no significant changes in urinary estrogen metabolites (estrone 3-glucuronide) or serum estradiol levels, serial semen parameters, or male sexual function by questionnaire. This study supports the idea that a threshold of weight loss is necessary to improve male reproductive function by reversing male hypogonadism, manifested as increased testosterone levels. Further serial semen analysis results showed normal ranges for most parameters despite massive weight loss.

Essentially all women are exposed to polycyclic aromatic hydrocarbons (PAHs), formed during incomplete combustion of organic materials, including fossil fuels, wood, foods, and tobacco. PAHs are ovarian toxicants in rodents, and cigarette smoking is associated with reproductive abnormalities in women. Biomonitoring of hydroxylated PAH (OH-PAH) metabolites in urine provides an integrated measure of exposure to PAHs via multiple routes and has been used to characterize exposure to PAHs in humans. We hypothesized that concentrations of OH-PAHs in urine are associated with reproductive function in women. We recruited women 18–44 years old, living in Orange County, California to conduct daily measurement of urinary luteinizing hormone (LH) and estrone 3-glucuronide (E13G) using a microelectronic fertility monitor for multiple menstrual cycles; these data were used to calculate endocrine endpoints. Participants also collected urine samples on cycle day 10 for measurement of nine OH-PAHs. Models were constructed for eight endpoints using a Bayesian mixed modeling approach with subject-specific random effects allowing each participant to act as a baseline for her set of measurements. We observed associations between individual OH-PAH concentrations and follicular phase length, follicular phase LH and E13G concentrations, preovulatory LH surge concentrations, and periovulatory E13G slope and concentration. We have demonstrated the feasibility of using urinary reproductive hormone data obtained via fertility monitors to calculate endocrine endpoints for epidemiological studies of ovarian function during multiple menstrual cycles. The results show that environmental exposure to PAHs is associated with changes in endocrine markers of ovarian function in women in a PAH-specific manner. Keywords: Polycyclic aromatic hydrocarbon, Ovarian function, Reproduction, Luteinizing hormone, Estradiol, Menstrual cycle

Background: For 15 months in 1981-1982, the commercial milk supply on the Hawaiian island of Oahu was contaminated with heptachlor epoxide, a metabolite of the insecticide heptachlor, resulting in gestational and/or lactational exposure to offspring of women who drank cow milk during that period. Objective: To determine whether gestational and lactational exposure to heptachlor epoxide alters reproductive function and age at puberty in men or women. Methods: 457 participants were recruited from a prior high school enrollment sampling frame of 20,000 adults born during 1981-1982 who lived on Oahu since at least first grade. Number of glasses of cow milk consumed weekly by the mother during the participant's gestation was used as a surrogate measure of heptachlor epoxide exposure. Reproductive function measures included semen analyses; reproductive hormones or their metabolites in daily urine specimens for one menstrual cycle; serum reproductive hormone levels in both sexes; and reported ages of onset for pubertal milestones. Results: We observed no strong associations of heptachlor epoxide exposure during gestation and lactation with reproductive endpoints. In females, heptachlor epoxide exposure was associated with longer luteal phase length and slower drop in the ratio of estradiol to progesterone metabolites after ovulation. In males, heptachlor epoxide exposure was weakly associated with higher serum follicle stimulating hormone and luteinizing hormone concentrations, but no dose-response relationship was apparent. Conclusions: The results provide limited evidence that gestational and lactational exposure to heptachlor epoxide, due to milk contamination on Oahu in 1981-1982, resulted in clinically significant disturbances of reproductive function in men or women. © 2012 Elsevier Inc.

Regression analysis was used to estimate and test for relationships between urinary pesticide metabolites and neurobehavioral test performance in adults, 20 to 59 years old, participating in the third National Health and Nutrition Examination Survey. The 12 pesticide metabolites included 2 naphthols, 8 phenols, a phenoxyacetic acid, and a pyridinol. The 3 neurobehavioral tests included in the survey were simple reaction time, symbol-digit substitution, and serial digit learning. As the 2,4-dichlorophenol, 2,5-dichlorophenol, and the pentachlorophenol concentrations increased, performance on the serial digit learning test improved. As the 2,5-dichlorophenol concentration increased, performance on the symbol-digit substitution test improved. At low concentrations, the parent compounds of these metabolites may act at acetylcholine and γ-aminobutyric acid synapses in the central nervous system to improve neurobehavioral test performance.

The genotoxicity of jet propulsion fuel 8 (JP-8) was assessed in the leukocytes of archived blood specimens from U.S. Air Force personnel using the comet assay. No differences in mean comet assay measurements were found between low, moderate, and high exposure groups before or after a 4h work shift. Before the work shift, mean tail DNA and mean tail (Olive) moment increased as the concentration of benzene measured in end-exhaled breath increased, indicating that prior environmental or work-related exposures to benzene produced DNA damage. The number of cells with highly damaged DNA decreased as the pre-shift benzene concentration in breath increased. It is not clear why the decrease is occurring. Mean tail DNA and mean tail (Olive) moment decreased as the concentrations of benzene and naphthalene measured in breath immediately after the work shift increased. These inverse relationships may reflect a slower rate of absorption or a faster rate of expiration of benzene in the lung. The number of cells with highly damaged DNA increased as the concentration of urinary (2-methoxyethoxy)acetic acid (MEAA) increased. This relationship was not seen in urinary MEAA adjusted for creatinine. MEAA is a metabolite of the deicing agent 2-(2-methoxyethoxy)ethanol contained in JP-8. MEAA or a component of JP-8 correlated with MEAA may have a toxic effect on DNA.

A study of workers exposed to jet fuel propellant 8 (JP-8) was conducted at U.S. Air Force bases and included the evaluation of three biomarkers of exposure: S-benzylmercapturic acid (BMA), S-phenylmercapturic acid (PMA), and (2-methoxyethoxy)acetic acid (MEAA). Postshift urine specimens were collected from various personnel categorized as high (n = 98), moderate (n = 38) and low (n = 61) JP-8 exposure based on work activities. BMA and PMA urinary levels were determined by high-performance liquid chromatography-tandem mass spectrometry (HPLC-MS/MS), and MEAA urinary levels were determined by gas chromatography-mass spectrometry (GC-MS). The numbers of samples determined as positive for the presence of the BMA biomarker (above the test method's limit of detection [LOD = 0.5 ng/ml]) were 96 (98.0%), 37 (97.4%), and 58 (95.1%) for the high, moderate, and low (control) exposure workgroup categories, respectively. The numbers of samples determined as positive for the presence of the PMA biomarker (LOD = 0.5 ng/ml) were 33 (33.7%), 9 (23.7%), and 12 (19.7%) for the high, moderate, and low exposure categories. The numbers of samples determined as positive for the presence of the MEAA biomarker (LOD = 0.1 μ g/ml) were 92 (93.4%), 13 (34.2%), and 2 (3.3%) for the high, moderate, and low exposure categories. Statistical analysis of the mean levels of the analytes demonstrated MEAA to be the most accurate or appropriate biomarker for JP-8 exposure using urinary concentrations either adjusted or not adjusted for creatinine; mean levels of BMA and PMA were not statistically significant between workgroup categories after adjusting for creatinine.

This article examines serious and fatal pneumatic nail gun (PNG) injury investigations for workplace, tool design, and human factors relevant to causation and resulting OSH authorities' responses in terms of citations and penalties.The U.S. Occupational Safety and Health Administration (OSHA) database of Fatality and Catastrophe Investigation Summaries (FCIS) were reviewed (1985-2012) to identify n = 258 PNG accidents.79.8% of investigations, and 100% of fatalities, occurred in the construction industry. Between 53-71% of injuries appear to have been preventable had a safer sequential trigger tool been used. Citations and monetary penalties were related to injury severity, body part injured, disabling of safety devices, and insufficient personal protective equipment (PPE).Differences may exist between construction and other industries in investigators interpretations of PNG injury causation and resulting citations/penalties. Violations of PPE standards were penalized most severely, yet the preventive effect of PPE would likely have been less than that of a safer sequential trigger.

Atrazine is the most commonly used herbicide in the U.S. and a wide-spread groundwater contaminant. Epidemiologic and laboratory evidence exists that atrazine disrupts reproductive health and hormone secretion. We examined the relationship between exposure to atrazine in drinking water and menstrual cycle function including reproductive hormone levels. Women 18-40 years old residing in agricultural communities where atrazine is used extensively (Illinois) and sparingly (Vermont) answered a questionnaire (n=102), maintained menstrual cycle diaries (n=67), and provided daily urine samples for analyses of luteinizing hormone (LH), and estradiol and progesterone metabolites (n=35). Markers of exposures included state of residence, atrazine and chlorotriazine concentrations in tap water, municipal water and urine, and estimated dose from water consumption. Women who lived in Illinois were more likely to report menstrual cycle length irregularity (odds ratio (OR)=4.69; 95% confidence interval (CI): 1.58-13.95) and more than 6 weeks between periods (OR=6.16; 95% CI: 1.29-29.38) than those who lived in Vermont. Consumption of >2 cups of unfiltered Illinois water daily was associated with increased risk of irregular periods (OR=5.73; 95% CI: 1.58-20.77). Estimated "dose" of atrazine and chlorotriazine from tap water was inversely related to mean mid-luteal estradiol metabolite. Atrazine "dose" from municipal concentrations was directly related to follicular phase length and inversely related to mean mid-luteal progesterone metabolite levels. We present preliminary evidence that atrazine exposure, at levels below the US EPA MCL, is associated with increased menstrual cycle irregularity, longer follicular phases, and decreased levels of menstrual cycle endocrine biomarkers of infertile ovulatory cycles.

The relationships between blood lead levels and serum follicle stimulating hormone and luteinizing hormone were assessed in a nationally representative sample of women, 35-60 years old, from the National Health and Nutrition Examination Survey 1999-2002. The blood lead levels of the women ranged from 0.2 to 17.0 μg/dL. The estimated geometric mean was 1.4 μg/dL, and the estimated arithmetic mean was 1.6 μg/dL. As the blood lead level increased, the concentration of serum follicle stimulating hormone increased in post-menopausal women, women who had both ovaries removed, and pre-menopausal women. The concentration of luteinizing hormone increased as blood lead level increased in post-menopausal women and women who had both ovaries removed. The lowest concentrations of blood lead at which a relationship was detected were 0.9 μg/dL for follicle stimulating hormone and 3.2 μg/dL for luteinizing hormone. Lead may act directly or indirectly at ovarian and non-ovarian sites to increase the concentrations of follicle stimulating hormone and luteinizing hormone.

To assess trends in risk factors for work-related musculoskeletal disorders (MSDs).Results from two similar national surveys (2002 and 2006) examined trends in relationships between individual, psychosocial, and physical factors and MSDs.Findings between years were similar, but important differences included a stronger effect of "Work Stress" on "Pain in Arms," and a stronger combined effect of "Hand Movement" and "Work Stress" on "Pain in Arms." Also, two interactions were statistically significant in the 2006 data, but not in the 2002 data, revealing potentially increased risks. These were "Hand Movement" and "Work Stress" on "Back Pain," and "Heavy Lifting" and "Work Stress" on "Pain in Arms."New strategies for preventing both low back and upper extremity MSDs should focus on work stress, heavy lifting, and hand movement, individually and in combination.

This study evaluated health care worker exposure to antineoplastic drugs.A cross-sectional study examined environmental samples from pharmacy and nursing areas. A 6-week diary documented tasks involving those drugs. Urine was analyzed for two specific drugs, and blood samples were analyzed by the comet assay.Sixty-eight exposed and 53 nonexposed workers were studied. Exposed workers recorded 10,000 drug-handling events during the 6-week period. Sixty percent of wipe samples were positive for at least one of the five drugs measured. Cyclophosphamide was most commonly detected, followed by 5-fluorouracil. Three of the 68 urine samples were positive for one drug. No genetic damage was detected in exposed workers using the comet assay.Despite following recommended safe-handling practices, workplace contamination with antineoplastic drugs in pharmacy and nursing areas continues at these locations.

The relationship between the blood lead concentration and cognitive function in children and adults with different VDR genotypes who participated in the third National Health and Nutrition Examination Survey was investigated. The relationship between blood lead and serum homocysteine concentrations was also investigated. In children 12 to 16 years old, performance on the digit span and arithmetic tests as a function of the blood lead concentration varied by VDR rs2239185 and VDR rs731236 genotypes. Decreases in performance occurred in some genotypes, but not in others. In adults 20 to 59 years old, performance on the symbol-digit substitution test as a function of the blood lead concentration varied by VDR rs2239185-rs731236 haplotype. In the 12 to 16 year old children and adults 60 or more years old, the relationship between the serum homocysteine and blood lead concentrations varied by VDR genotype. The mean blood lead concentrations of the children and adults did not vary by VDR genotype.

The relationship between the blood lead concentration and cognitive function in children and adults with different ALAD genotypes who participated in the third National Health and Nutrition Examination Survey was investigated. The relationship between blood lead and serum homocysteine concentrations was also investigated. In children 12 to 16 years old, no difference in the relationship between cognitive function and blood lead concentration between genotypes was found. In adults 20 to 59 years old, mean reaction time decreased as the blood lead concentration increased in the ALAD rs1800435 CC/CG group. This represents an improvement in performance. In adults 60 years and older, no difference in the relationship between cognitive function and blood lead concentration between genotypes was found. The serum homocysteine concentration increased as the blood lead concentration increased in adults 20 to 59 years old and 60 years and older, but there were no differences between genotypes. The mean blood lead concentration of children with the ALAD rs1800435 CC/CG genotype was less than that of children with the GG genotype.

Regression analysis was used to estimate and test for relationships between blood lead, serum folate, red blood cell folate, serum vitamin B12, serum homocysteine, and neurobehavioral test performance in adults, 20-59 years old, participating in the third National Health and Nutrition Examination Survey. The three neurobehavioral tests included in the survey were simple reaction time, symbol-digit substitution, and serial digit learning. Serum folate, red blood cell folate, and serum vitamin B12 decreased as the blood lead concentration increased. Serum homocysteine increased as the blood lead concentration increased. Serum homocysteine decreased as the serum folate and serum vitamin B12 concentrations increased. Neurobehavioral test performance was not related to the blood lead, serum folate, or serum vitamin B12 concentrations. In adults 20-39 years old, performance on the serial digit learning test improved as the serum homocysteine concentration increased. In adults 40-59 years old, neurobehavioral test performance was not related to the serum homocysteine concentration. Homocysteine may impair cognitive function by acting at N-methyl-D-aspartate receptors, and improve cognitive function by acting at N-methyl-D-aspartate or gamma-aminobutyric acid receptors.

To determine whether the Occupational Information Network (O*NET) database can be used to identify job dimensions to serve as proxy measures for psychosocial factors and select environmental factors, and to determine whether these factors could be linked to national health surveys to examine associations with health risk behaviors and outcomes.Job characteristics were obtained from O*NET 98. Health outcomes were obtained from two national surveys. Data were linked using Bureau of Census codes. Multiple logistic regression was used to examine associations between O*NET factors and cardiovascular disease, depression, and health risk factors.Seven of nine work organization or psychosocial factors were significantly associated with health risk behaviors in both the National Health and Nutrition Examination Survey III and National Health Interview Survey.This study demonstrates a method for linking independently obtained health and job characteristic data based on occupational code.

This study investigated the effects of screwdriver handle shape, surface, and workpiece orientation on subjective discomfort, number of screw-tightening rotations, screw-insertion time, axial screwdriving force, and finger contact forces in a screwdriving task. Handles with three longitudinal cross-sectional shapes (circular, hexagonal, triangular), four lateral shapes (cylindrical, double frustum, reversed double frustum, cone), and two surface materials (plastic, rubber coated) were tested. Individual phalangeal segment force distributions indicated how fingers and phalangeal segments were involved in the creation of total finger force (15.0%, 34.6%, 34.5%, and 15.9% for the index, middle, ring, and little fingers; and 45.7%, 22.4%, 12.9%, and 19.0% for the distal, middle, proximal, and metacarpal phalanges, respectively). From this finding, the index and little fingers appeared to contribute mainly in the guiding and balancing of the screwdriver handles, whereas middle and ring fingers played a more prominent role in gripping and turning. Participants preferred circular and hexagonal longitudinal-shaped and double frustum and cone lateral-shaped handles over the triangular longitudinal-shaped handles, and cylindrical and reversed double frustum lateral-shaped handles. Circular, cylindrical, and double frustum handles exhibited the least total finger force associated with screw insertion. In terms of combinations of longitudinal and lateral shapes, circular with double frustum handles were associated with less discomfort and total finger force.

In an earlier report, Platek et al. (1985) presented the results of an 18-month inhalation exposure of rats and monkeys to short chrysotile asbestos. The mean chamber exposure level was 1.0 mg/m(3) with an average of 0.79 fibers/ml5 microm in length. Gross and histopathological examination of exposed and control rats indicated no treatment-related lesions. Asbestos bodies adjacent to the terminal bronchioles, but no fibrosis, were found in lung biopsy tissue taken from the exposed monkeys at 10 months post-exposure. Fifteen monkeys (9 exposed and 6 controls) from this study were maintained for 11.5 years following exposure. Lung fiber burdens were determined by transmission electron microscopy. The mean lung burden (+/- standard deviation) for 59 samples from exposed monkeys was 63 +/- 30 x 10(6) fibers/g dry lung (range, 18-139 x 10(6)). The geometric mean fiber length was 3.5 microm with 35% of the fibers being5 microm in length. These data indicate some chrysotile fibers are durable in vivo for a significant period of time. Lungs were examined grossly and microscopically. No lesions attributable to the inhalation exposure were noted. Asbestos bodies were seen in the lungs of treated monkeys, primarily in the interstitium near bronchioles or small pulmonary blood vessels (which also may have been near to bronchioles just out of the plane of section).

The relationships between blood lead levels and serum follicle stimulating hormone and luteinizing hormone were assessed in a nationally representative sample of women, 35–60 years old, from the third National Health and Nutrition Examination Survey. The blood lead levels of the women ranged from 0.7 to 31.1 μ g/dl. The estimated geometric mean was 2.2 μ g/dl, and the estimated arithmetic mean was 2.8 μ g/dl. As the blood lead level increased across women, the concentration of serum follicle stimulating hormone increased in post-menopausal women, women who had both ovaries removed, and pre-menopausal women. The concentration of follicle stimulating hormone decreased in pre-menopausal women who were taking birth control pills. The concentration of luteinizing hormone increased as blood lead level increased in post-menopausal women and women who had both ovaries removed. The lowest concentrations of blood lead at which a relationship was detected were 1.7 μ g/dl for follicle stimulating hormone and 2.8 μ g/dl for luteinizing hormone. The increase in follicle stimulating hormone and luteinizing hormone in women with no ovaries indicates that lead may act at a non-ovarian site in the female reproductive system, along with a possible effect on the ovaries.

A compound capable of preventing age-related hearing loss would be very useful in an aging population. N-acetyl-L-cysteine (L-NAC) has been shown to be protective against noise exposure, a condition that leads to increased oxidative stress. Not withstanding environmental factors, there is evidence that age-related hearing loss (AHL) in the mouse is linked to more than one genetic loci and, by extension, in humans. Our hypothesis is that AHL defect results in increased sensitivity to oxidative stress and L-NAC would be able to protect the hearing of a mouse model of pre-mature AHL, the C57BL/6J (B6) mouse strain. L-NAC was added to the regular water bottle of B6 mice (experimental group) and available ad lib. The other group received normal tap water. Hearing was tested monthly by the ability to generate the auditory brainstem response (ABR). After the final ABR test, mice were sacrificed by an overdose of Avertin, ears were harvested and hair cell loss was quantified. There was no difference in ABR thresholds or in histopathology between the control group and the group receiving L-NAC in their drinking water. In contrast to the protective effects of L-NAC against noise-induced hearing loss, the lack of protective effect in this study may be due to (i) the dosage level; (ii) the duration of treatment; (iii) the biochemical mechanisms underlying age-induced hearing loss; or (iv) how the mouse metabolizes L-NAC.

This study investigated manual forces associated with trigger start (TS) and push to start (PTS) activation in-line electric screwdriver designs.The vertically directed axial screwdriver force transmitted with the driver to the fastener and the grip/finger forces on the driver handle were measured from 13 employees in an electronics assembly manufacturing facility. The PTS driver was associated with significantly (p .01) higher axial force than the TS driver at two of the four workstations, where the difference was as high as a 184% increase (36.5 vs. 103.8 N). Total finger force on the screwdriver handle was also higher for the PTS screwdriver (p .01). The PTS screwdriver may reduce instances of fastener head damage (“cam out”) by requiring a minimum level of axial force to ensure better contact between the screwdriver bit and the fastener. However, this appears to come at the expense of greater manual forces exerted by the operator. © 2007 Wiley Periodicals, Inc.

Pneumatic nail guns used in wood framing are equipped with one of two triggering mechanisms. Sequential actuation triggers have been shown to be a safer alternative to contact actuation triggers because they reduce traumatic injury risk. However, the sequential actuation trigger must be depressed for each individual nail fired as opposed to the contact actuation trigger, which allows the trigger to be held depressed as nails are fired repeatedly by bumping the safety tip against the workpiece. As such, concerns have been raised about risks for cumulative trauma injury, and reduced productivity, due to repetitive finger motion with the sequential actuation trigger.This study developed a method to predict cumulative finger flexor tendon travel associated with the sequential actuation trigger nail gun from finger joint kinematics measured in the trigger actuation and productivity standards for wood-frame construction tasks.Finger motions were measured from six users wearing an instrumented electrogoniometer glove in a simulation of two common framing tasks-wall building and flat nailing of material. Flexor tendon travel was calculated from the ensemble average kinematics for an individual nail fired.Finger flexor tendon travel was attributable mostly to proximal interphalangeal and distal interphalangeal joint motion. Tendon travel per nail fired appeared to be slightly greater for a wall-building task than a flat nailing task. The present study data, in combination with construction industry productivity standards, suggest that a high-production workday would be associated with less than 60 m/day cumulative tendon travel per worker (based on 1700 trigger presses/day).These results suggest that exposure to finger tendon travel from sequential actuation trigger nail gun use may be below levels that have been previously associated with high musculoskeletal disorder risk.

To report trends for the risk of musculoskeletal disorders.Three Quality of Work Life surveys examine the risk factors for musculoskeletal disorders.Findings similar for several risk factors, but differences across the reporting years may reflect economic conditions. Respondent numbers in 2010 were reduced, some risk factors had pattern changes, and there were sex and age differences. Trend analysis showed most significant changes were for the "work fast" risk factor. New 2010 "physical effort" item showed sex differences, and items reflective of total worker health showed strong associations with "back pain" and "pain in arms."Intervention strategies should focus on physical exposures and psychosocial risk factors (work stress, safety climate, job satisfaction, supervisor support, work fast, work freedom, work time) that have been consistently related to reports of musculoskeletal disorders. Economic conditions will influence some psychosocial risk factors.

In the absence of a US Food and Drug Administration (FDA)-cleared latex skin testing reagent, in vitro tests remain important for the diagnosis of latex allergy.To evaluate the performance characteristics of IMMULITE 2000 3gAllergy (Immulite), a third-generation, FDA-cleared, continuous random-access immunoanalyzer, for the quantification of latex specific IgE.Stored serum samples (N = 201) from patients classified as having positive or negative latex puncture skin test results were measured for latex specific IgE levels using Immulite, and these data were compared with historical results from 3 second-generation, FDA-cleared IgE antilatex assays (AlaSTAT [Ala], AutoCAP [CAP], and HY*TEC enzyme immunoassay [HT]).The diagnostic performances of the CAP, Ala, and Immulite assays (or = 0.35 kU/L cutoff value) were equivalent in sensitivity and specificity (P.05). The HT assay (or = 0.05 kU/L cutoff value) was more sensitive and less specific (P.05). Immulite (or = 0.10 kU/L cutoff value) had greater sensitivity than Ala and CAP and greater specificity than HT (P.05 for both). Diagnostic efficiency was greater for Immulite than for CAP, Ala, and HT (P.05).The Immulite system is superior in diagnostic performance, especially at the 0.10 kU/L or greater cutoff level, for the diagnosis of latex allergy compared with older, second-generation assays. Immulite still misclassifies 15.5% of puncture skin test-positive individuals as negative for latex specific IgE. Compared with second-generation assays, Immulite represents a technological advance, with enhanced speed and less operator intervention.

1-Bromopropane (1-BP; n -propyl bromide) (CAS No. 106-94-5) is an alternative to ozone-depleting chlorofluorocarbons that has a variety of potential applications as a degreasing agent for metals and electronics, and as a solvent vehicle for spray adhesives. Its isomer, 2-brompropane (2-BP; isopropyl bromide) (CAS No. 75-26-3) impairs antioxidant cellular defenses, enhances lipid peroxidation, and causes DNA damage in vitro. The present study had two aims. The first was to assess DNA damage in human leukocytes exposed in vitro to 1- or 2-BP. DNA damage was also assessed in peripheral leukocytes from workers with occupational exposure to 1-BP. In the latter assessment, start-of- and end-of-work week blood and urine samples were collected from 41 and 22 workers at two facilities where 1-BP was used as a solvent for spray adhesives in foam cushion fabrication. Exposure to 1-BP was assessed from personal-breathing zone samples collected for 1–3 days up to 8 h per day for calculation of 8 h time weighted average (TWA) 1-BP concentrations. Bromide (Br) was measured in blood and urine as a biomarker of exposure. Overall, 1-BP TWA concentrations ranged from 0.2 to 271 parts per million (ppm) at facility A, and from 4 to 27 ppm at facility B. The highest exposures were to workers classified as sprayers. 1-BP TWA concentrations were statistically significantly correlated with blood and urine Br concentrations. The comet assay was used to estimate DNA damage. In vitro, 1- or 2-BP induced a statistically significant increase in DNA damage at 1 mM. In 1-BP exposed workers, start-of- and end-of-workweek comet endpoints were stratified based on job classification. There were no significant differences in DNA damage in leukocytes between workers classified as sprayers (high 1-BP exposure) and those classified as non-sprayers (low 1-BP exposure). At the facility with the high exposures, comparison of end-of-week values with start-of-week values using paired analysis revealed non-sprayers had significantly increased comet tail moments, and sprayers had significantly increased comet tail moment dispersion coefficients. A multivariate analysis included combining the data sets from both facilities, log transformation of 1-BP exposure indices, and the use of multiple linear regression models for each combination of DNA damage and exposure indices including exposure quartiles. The covariates were gender, age, smoking status, facility, and glutathione S -transferase M1 and T1 (GSTM1, GSTT1) polymorphisms. In the regression models, start-of-week comet tail moment in leukocytes was significantly associated with serum Br quartiles. End-of-week comet tail moment was significantly associated with 1-BP TWA quartiles, and serum Br quartiles. Gender, facility, and GSTM1 had a significant effect in one or more models. Additional associations were not identified from assessment of dispersion coefficients. In vitro and in vivo results provide limited evidence that 1-BP exposure may pose a small risk for increasing DNA damage.

Objectives. The goals of this study were two-fold: ( 1) to assess the relationship between blood lead levels and neurobehavioral test performance in a nationally representative sample of adults from the third National Health and Nutrition Evaluation Survey and ( 2) to analyze the results from previously published studies of occupational lead exposure that used the same neurobehavioral tests as those included in the survey. Methods. Regression models were used to test and estimate the relationships between measurements of blood lead and performance on a simple reaction time, a symbol-digit substitution, and a serial digit learning test in adults aged 20–59 years who participated the survey. Mixed models were used to analyze the data from the occupational studies. Results. The blood lead levels of those participating in the survey ranged from 0.7 to 41.8 μg/dl. The estimated geometric mean was 2.51 μg/dl, and the estimated arithmetic mean was 3.30 μg/dl. In the survey, no statistically significant relationships were found between blood lead concentration and performance on the three neurobehavioral tests when adjusted for covariates. In the occupational studies, the groups exposed to lead consistently performed worse than control groups on the simple reaction time and digit-symbol substitution tests. Conclusions. The results from the survey and the occupational studies do not provide evidence for impairment of neurobehavioral test performance at levels below 25 μg/dl, the concentration that the Centers for Disease Control and Prevention define as elevated in adults. The average blood lead level of the exposed groups in the occupational studies was 41.07 μg/dl, less than 50 μg/dl, the minimum concentration that the Occupational Safety and Health Administration requires for medical removal from the workplace. Given the evidence of impaired neurobehavioral performance in these groups, the 50 μg/dl limit should be reevaluated.

Audiometry and exposure measurements were conducted on workers from fiberglass and metal products manufacturing plants and a mail distribution terminal (N = 313). Workers exposed to noise and styrene had significantly worse pure-tone thresholds at 2, 3, 4, and 6 kHz when compared with noise-exposed or nonexposed workers. Age, noise exposure, and urinary mandelic acid (a biologic marker for styrene) were the variables that met the significance level criterion in the multiple logistic regression. The odds ratios for hearing loss were 1.19 for each increment of 1 year of age (95% confidence interval [CI], 1.11-1.28), 1.18 for every decibel >85 dB(A) of noise exposure (95% CI, 1.01-1.34), and 2.44 for each millimole of mandelic acid per gram of creatinine in urine (95% CI, 1.01-5.89). Our findings suggest that exposure to styrene even below recommended values had a toxic effect on the auditory system.

Objective: To compare urinary levels of reproductive hormones in African American and Caucasian women. Design: Cross-sectional study. Setting: Ten United States Air Force (USAF) bases. Patient(s): African American (n = 33) and Caucasian (n = 65) women of reproductive age from a larger study of USAF women (n = 170). Intervention(s): None. Main Outcome Measure(s): Urinary endocrine end points: follicular luteinizing hormone (LH), preovulatory LH, level of LH surge peak, early follicular follicle stimulating hormone (FSH), follicular LH:FSH ratio, midluteal FSH, FSH rise before menses, early follicular estrone 3-glucuronide (E 1 3G), midfollicular E 1 3G, periovulatory E 1 3G peak, midluteal E 1 3G, early follicular pregnanediol 3-glucuronide (Pd3G), follicular Pd3G, rate of periovulatory Pd3G increase, E 1 3G:Pd3G on the day of luteal transition, slope of E 1 3G:Pd3G, and midluteal Pd3G. Result(s): Relative to Caucasians, African American women had significantly lower follicular phase LH:FSH ratios (mean ± SD: 0.7 ± 0.4 vs. 1.0 ± 0.6), lower follicular phase Pd3G levels (1.0 ± 0.5 vs. 1.2 ± 0.8 μg/mg creatinine), and lower rates of periovulatory Pd3G increase (0.5 ± 0.7 vs. 1.0 ± 1.2 μg/mg creatinine). Conclusion(s): Findings of this analysis should be considered preliminary evidence of racial differences in hormone levels. Future studies are needed to determine whether these differences have clinical significance.

Toluene is the most widely used industrial solvent. It has been shown to be ototoxic in mice and rats, and to increase permanent threshold shift in conjunction with exposure to noise. Chinchillas are widely used for studying noise effects on the cochlea. The present study was initiated to study toluene and noise interaction in chinchillas. Thirty-three chinchillas were exposed to a 95 dBA 500 Hz octave band noise plus 2000 ppm toluene, 8 or 12 h per day for 10 days. Auditory function was estimated using the auditory brainstem response (ABR) to tones between 500 Hz and 16 kHz. There was no effect on the ABR of toluene alone. Noise alone produced a threshold shift. There was no interaction of noise and toluene on the ear. The present study suggests that chinchillas are markedly less susceptible to the ototoxic effect of toluene than mice and rats. A working hypothesis as to the species differences was that chinchilla liver was able to detoxify the toluene. Hepatic microsomes from chinchillas, rats and humans were tested for their ability to convert toluene to the more water-soluble compound - benzyl alcohol. Chinchilla livers were found to contain more of the P450 enzymes CYP2E1 and CYP2B than rats or humans. In addition, the data show that the P450 enzymes are more active in chinchillas than in rats and humans. In conclusion, the results suggest that rats and mice are a more appropriate model for human toluene ototoxicity. However, chinchillas may provide a valuable model for investigating how ototoxic agents can be detoxified to less damaging compounds.

The NIOSH health hazard evaluation program evaluated employees’ exposures to high level continuous and impact noise at a hammer forge company. Personal dosimetry data were collected from 38 employees and noise exposure recordings were collected during two visits to the facility. Extensive audiometric records were reviewed and trends for hearing loss, threshold shifts and risk of hearing loss were assessed. The effectiveness of hearing protection devices for hammer forging was evaluated with an acoustic test fixture. A longitudinal analysis was conducted on the audiometric data set that included 4750 audiograms for 483 employees for the years 1981 to 2006. The analysis of the audiometric history for the employees showed that 82% had experienced a NIOSH-defined hearing threshold shift and 63% had experienced an OSHA-defined standard threshold shift. The mean number of years from a normal baseline audiogram to a threshold shift was about 5 years for a NIOSH threshold shift and was about 9 years for an OSHA t...

Receiver operating characteristics (ROC) analyses to evaluate and compare the diagnostic accuracy of Food and Drug Administration (510K)-cleared natural rubber latex (NRL)-specific immunoglobulin E (IgE) antibody immunoassays have not been performed using well-characterized skin-testing reagents. Sera were collected from 311 subjects (131 latex puncture skin test [PST] positive and 180 PST negative). All masked, coded sera were analyzed for latex-specific IgE antibodies in the Diagnostic Products Corporation microplate AlaSTAT, HYCOR HY-TEC RAST, and Pharmacia-Upjohn CAP System RAST FEIA (CAP). Diagnostic accuracy was evaluated using GraphRoc for Windows software to construct and analyze ROC curves in relation to the subjects' PST status and the results of the immunoassays. The ROC areas under the curve (AUCs) ± standard error based on PST for the three diagnostic tests were 0.858 ± 0.024, 0.869 ± 0.024, and 0.924 ± 0.017, respectively, for AlaSTAT, CAP, and HY-TEC. The HY-TEC system had a significantly greater AUC based on PST than those observed for AlaSTAT ( P < 0.05) and CAP ( P < 0.05) analyses. When the diagnostic tests were probed as to the cutoffs giving maximal diagnostic efficiency compared to PST, CAP and AlaSTAT yielded values of A )/liter and

The third National Health and Nutrition Examination Survey (NHANES III) contained three computerized neurobehavioral tests from the Neurobehavioral Evaluation System (NES): simple reaction time, symbol-digit substitution and serial digit learning. The neurobehavioral data that were collected came from a nationally representative sample of adults 20-59 years old. Performance on the tests was related to sex, age, education level, family income and race-ethnicity. Performance decreased as age increased, and increased as education level and family income increased. Differences in performance between sexes, levels of education and racial-ethnic groups tended to decrease as family income increased. The relationship between age and performance on the symbol-digit substitution test varied by education level and by racial-ethnic group. The relationship between age and performance on the serial digit learning test varied by racial-ethnic group. Questionnaire variables that were related to performance on one or more of the tests included the reported amount of last night's sleep, energy level, computer or video game familiarity, alcoholic beverages within the last 3 h and effort. Persons who took the tests in English or Spanish performed differently on the symbol-digit substitution and serial digit learning tests. Performance on all the tests decreased as test room temperature increased.

Chlorpyrifos is a moderately toxic organophosphate pesticide. Houses and lawns in the United States receive a total of approximately 20 million annual chlorpyrifos treatments, and 82% of U.S. adults have detectable levels of a chlorpyrifos metabolite (3,5, 6-trichloro-2-pyridinol; TCP) in the urine. The U.S. Environmental Protection Agency has estimated that there are 5,000 yearly reported cases of accidental chlorpyrifos poisoning, and approximately one-fourth of these cases exhibit symptoms. Organophosphates affect the nervous system, but there are few epidemiologic data on chlorpyrifos neurotoxicity. We studied neurologic function in 191 current and former termiticide applicators who had an average of 2.4 years applying chlorpyrifos and 2.5 years applying other pesticides, and we compared them to 189 nonexposed controls. The average urinary TCP level for 65 recently exposed applicators was 629.5 microg/L, as compared to 4.5 microg/L for the general U.S. population. The exposed group did not differ significantly from the nonexposed group for any test in the clinical examination. Few significant differences were found in nerve conduction velocity, arm/hand tremor, vibrotactile sensitivity, vision, smell, visual/motor skills, or neurobehavioral skills. The exposed group did not perform as well as the nonexposed group in pegboard turning tests and some postural sway tests. The exposed subjects also reported significantly more symptoms, including memory problems, emotional states, fatigue, and loss of muscle strength; our more quantitative tests may not have been adequate to detect these symptoms. Eight men who reported past chlorpyrifos poisoning had a pattern of low performance on a number of tests, which is consistent with prior reports of chronic effects of organophosphate poisoning. Overall, the lack of exposure effects on the clinical examination was reassuring. The findings for self-reported symptoms raise some concern, as does the finding of low performance for those reporting prior poisoning. Although this was a relatively large study based on a well-defined target population, the workers we studied may not be representative of all exposed workers, and caution should be exercised in generalizing our results.

Equations for calculating the biases induced by coarse measurement scales are derived. Equations for the expected value, variance, covariance, correlation coefficient, and reliability coefficient are provided. The equations can be used to study the effects of measurement scale coarseness. Examples are given that illustrate that biases can vary depending on the mean and variance of the quantities being measured, the number of scale points, the rule for assigning quantities to scale points, and the number of items in a scale. Equations for the bias limits are also derived. Under some conditions, the biases disappear as the number of scale points increases. To avoid bias, it is recommended that graphic rating scales be used.

The CBA/CaJ (CB) and C57BL/6J (B6) inbred strains of mice were exposed for 1 h to noise intensities between 98 and 119 dB SPL. Previous studies indicated that the B6 mice exhibited permanent threshold shifts (PTS) after 1 h exposure to 110 dB, whereas the CB mice did not exhibit any PTS. These differences in susceptibility to noise-induced hearing loss (NIHL) appear to be due to a gene for age-related hearing loss (AHL). The current study was designed to determine dose-response curves for NIHL over the ranges of intensities of noise that would characterize the B6 and CB inbred strains of mice. Because of the considerable differences in sensitivity to NIHL, the noise exposures for the two strains overlapped only at 110 and 113 dB. Nevertheless, the two strains exhibited two different dose-response curves, offset and with different slopes. We postulate that the B6 strain of mice exhibits a more linear increase for PTS from 98–113 dB, consistent with incremental effects on some metabolic physiological mechanism(s); the abrupt transition in NIHL between 113 and 116 dB for the CB mice is consistent with an ototraumatic structural injury.

Background: In the absence of Food and Drug Administration–approved natural rubber latex skin testing reagents, latex-specific IgE antibody immunoassays are used in the diagnosis of latex allergy. Comparative diagnostic performance of these tests has not been definitively determined. Objective: We sought to study the predictive value of available Food and Drug Administration (510K)–cleared latex-specific IgE antibody immunoassays in the diagnosis of latex allergy. Methods: Subjects (n = 312) were classified as having a positive (n = 117) or a negative (n = 195) latex allergy history (Hx) or having a positive (n = 131) or a negative (n = 181) puncture skin test (PST) response (Greer reagent). The 14 subjects with a negative Hx and a positive PST response had negative responses to glove provocation testing and thus were considered sensitized but asymptomatic. Sera from 22 subjects were split to evaluate intra-assay variation. All 334 coded sera were analyzed for latex-specific IgE antibodies in the Diagnostic Products Corporation microplate AlaSTAT, Hycor HY-TEC EIA System, and Pharmacia-UpJohn CAP System. Variance and diagnostic performance parameters of each test were computed with 95% confidence intervals in relation to the subjects' Hx and PST status. Results: Intra-assay concordance of split sera results was 96.0% for all 3 assays, with coefficients of variation of less than 25% and between-assay coefficients of variation of less than 21%. The diagnostic performance of the CAP and AlaSTAT assays were equivalent in comparison with PST results: sensitivity, CAP 76.3% and ALASTAT 73.3% and specificity, CAP 96.7% and AlaSTAT 97.2% ( P = NS). The HY-TEC assay was more sensitive (91.6%) and less specific (73.3%) than the CAP and AlaSTAT assays ( P Conclusion: The CAP and AlaSTAT assays produce 24% and 27% of false-negative results, respectively, whereas the HY-TEC produces 27% of false-positive results when compared with the PST. (J Allergy Clin Immunol 1999;103:925-30.)

Radiofrequency (RF) radiation is used in a variety of workplaces. In addition to RF radiation, many workers are concurrently exposed to numerous chemicals; exposed workers include those involved with the microelectronics industry, plastic sealers, and electrosurgical units. The developmental toxicity of RF radiation is associated with the degree and duration of hyperthermia induced by the exposure. Previous animal research indicates that hyperthermia induced by an elevation in ambient temperature can potentiate the toxicity and teratogenicity of some chemical agents. We previously demonstrated that combined exposure to RF radiation (10 MHz) and the industrial solvent, 2-methoxyethanol (2ME), produces enhanced teratogenicity in rats. The purpose of the present research is to determine the effects of varying the degree and duration of hyperthermia induced by RF radiation (sufficient to maintain colonic temperatures at control [38.5], 39.0, 40.0, or 41.0 degrees C for up to 6 h) and 2ME (100 mg/kg) administered on gestation day 13 of rats. Focusing on characterizing the dose-response pattern of interactions, this research seeks to determine the lowest interactive effect level. Day 20 fetuses were examined for external and skeletal malformations. The results are consistent with previous observations. Significant interactions were observed between 2ME and RF radiation sufficient to maintain colonic temperatures at 41 degrees C for 1 h, but no consistent interactions were seen at lower temperatures even with longer durations. These data indicate that combined exposure effects should be considered when developing both RF radiation and chemical exposure guidelines and intervention strategies.