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We performed a meta-analysis of epidemiological results for the association between occupational exposure as a firefighter and cancer as part of the broader evidence synthesis work of the IARCMonographsprogram.

I INTRODUCTION One of the most important issues for science in the courtroom is the determination of causality. Like science in the courtroom, science in the regulatory arena can also [...]

Paracetamol (N-acetyl-p-aminophenol (APAP), otherwise known as acetaminophen) is the active ingredient in more than 600 medications used to relieve mild to moderate pain and reduce fever. APAP is widely used by pregnant women as governmental agencies, including the FDA and EMA, have long considered APAP appropriate for use during pregnancy when used as directed. However, increasing experimental and epidemiological research suggests that prenatal exposure to APAP might alter fetal development, which could increase the risks of some neurodevelopmental, reproductive and urogenital disorders. Here we summarize this evidence and call for precautionary action through a focused research effort and by increasing awareness among health professionals and pregnant women. APAP is an important medication and alternatives for treatment of high fever and severe pain are limited. We recommend that pregnant women should be cautioned at the beginning of pregnancy to: forego APAP unless its use is medically indicated; consult with a physician or pharmacist if they are uncertain whether use is indicated and before using on a long-term basis; and minimize exposure by using the lowest effective dose for the shortest possible time. We suggest specific actions to implement these recommendations. This Consensus Statement reflects our concerns and is currently supported by 91 scientists, clinicians and public health professionals from across the globe.

Wastewater-based epidemiology provides an opportunity for near real-time, cost-effective monitoring of community-level transmission of SARS-CoV-2. Detection of SARS-CoV-2 RNA in wastewater can identify the presence of COVID-19 in the community, but methods for estimating the numbers of infected individuals on the basis of wastewater RNA concentrations are inadequate.

Inconsistent findings from recent mortality studies of workers exposed to magnetic fields have led to calls for more detailed understanding of exposure distributions and metrics in various industries. The authors undertook personal monitoring at an automobile transmission plant to (a) learn if magnetic field exposure differences were present, (b) make assignments for a brain cancer study, and (c) compare two exposure indices. A wide range of average exposures occurred (i.e., 0.016-4.6 microtesla). Within-day variability was also large, and it reached 4 orders of magnitude for some workers. Unexpectedly, demagnetizers were found among the strong sources that contributed to elevated exposures. The authors used conventional summary measures to assign job groups to exposure categories, and they used a new index of exposure irregularity to make alternative assignments. These new assignments appeared to differ from the original ones with respect to work time in each exposure group (i.e., 54% of the work time fell into different exposure categories)., RECENT STUDIES of the possible association between workplace exposure to magnetic fields (MFs) and certain cancers are superior to earlier studies because workplace measurements were used as the basis for [...]

The cumulative daily average wet-bulb globe temperature (WBGT) index, over one or two preceding days, is a better measure for predicting cases of exertional heat illness (EHI) than current daily average WBGT, which is the standard heat index used by the Marine Corps. The results provide a simple index for use in predicting EHI risk that includes the dry-bulb temperature and the relative humidity.

ObjectiveViolence from care recipients and family members, including both verbal and physical abuse, is a serious occupational hazard for healthcare and social assistance workers. Most workplace violence studies in this sector focus on hospitals and other institutional settings. This study examined verbal abuse in a large home care (HC) aide population and evaluated risk factors.MethodsWe used questionnaire survey data collected as part of a larger mixed methods study of a range of working conditions among HC aides. This paper focuses on survey responses of HC aides (n=954) who reported on verbal abuse from non-family clients and their family members. Risk factors were identified in univariate and multivariable analyses.ResultsTwenty-two per cent (n=206) of aides reported at least one incident of verbal abuse in the 12 months before the survey. Three factors were found to be important in multivariable models: clients with dementia (relative risk (RR) 1.38, 95% CI 1.07 to 1.78), homes with too little space for the aide to work (RR 1.52, 95% CI 1.17 to 1.97) and predictable work hours (RR 0.74, 95% CI 0.58 to 0.94); two additional factors were associated with verbal abuse, although not as strongly: having clients with limited mobility (RR 1.35, 95% CI 0.94 to 1.93) and an unclear plan for care delivery (RR 1.27, 95% CI 0.95 to 1.69). Aides reporting verbal abuse were 11 times as likely to also report physical abuse (RR 11.53; 95% CI 6.84 to 19.45).ConclusionsVerbal abuse is common among HC aides. These findings suggest specific changes in work organisation and training that may help reduce verbal abuse.

The authors studied the respiratory effects of formaldehyde exposure among students who dissected cadavers in a gross anatomy laboratory. Peak expiratory flow and respiratory symptoms were measured before and after each weekly laboratory session. Each of 38 students was exposed to formaldehyde for 2.5 hr/wk for 14 wk. Individual, daily formaldehyde measurements averaged 1.1 ppm (standard deviation = 0.56 ppm). Multivariate models demonstrated two different time scales of effect of formaldehyde on peak expiratory flow: (1) exposure during the previous 2.5 hr reduced peak expiratory flow by -1.0% per ppm, and (2) average exposure during all preceding weeks reduced peak expiratory flow by an additional -0.5 % per ppm of formaldehyde. However, the short-term exposure effect was diminished during the first 4 wk, suggesting at least partial acclimatization. Symptom reporting was also associated with exposure during the previous 2.5 hr, and similar evidence of acclimatization was observed. These results suggest that there are two different time scales of response to formaldehyde, and they emphasize the need for longitudinal studies, characterized by quantitative exposure characterization, and frequent measurements of outcome., EPIDEMIOLOGIC INVESTIGATIONS of the effects of irritants on airway function are difficult because health endpoints tend to be reversible, there is wide variability of responsiveness among subjects, and individuals tend [...]

ObjectivesTo investigate the association between occupational lifting and the risk of rhegmatogenous retinal detachment (RRD) using data from a large population of men.MethodsWe used data from a national cohort of 49 321 Swedish men conscripted for compulsory military service in 1969–1970. We collected information on surgically treated RRD from the National Patient Register and we followed up the cohort between 1991 and 2009 at ages 40–60 years. Exposure to occupational lifting was assessed by applying a job exposure matrix to occupational data from the 1990 census. Incidence rate ratios (IRRs) and 95% CIs were estimated through Poisson regression models adjusted by degree of myopia, income and education level.ResultsWe observed 217 cases of RRD in 7 80 166 person-years. In univariate analyses we did not observe an association between occupational lifting and RRD. However, after adjustment for myopia and socioeconomic factors, we found an increased risk of RRD (IRR 2.38, 95% CI 1.15 to 4.93) for subjects in the highest category of exposure compared with those in the lowest one. The incidence rate of RRD among subjects lifting heavy loads at least twice per week, aged between 50 years and 59 years, and affected by severe myopia was as high as 7.9 cases per 1000 person-years, compared with an overall rate of 0.28.ConclusionsOur study supports the hypothesis that heavy occupational lifting is a risk factor for RRD. Information on myopia degree and socioeconomic status is necessary when studying the association between occupational lifting and RRD.

(Abstracted from Nat Rev Endocrinol2021;17:757–766)Paracetamol, otherwise known as acetaminophen, is the active ingredient in over 600 prescription and nonprescription analgesic and antipyretic medications. Worldwide and in the United States, more than 50% and 65% of pregnant women use acetaminophen, respectively.

THE WORLD'S worst industrial disaster occurred at approximately midnight on December 2 and 3, 1984, at the Union Carbide plant in Bhopal, India. More than 200 000 persons were exposed [...]

OBJECTIVETo estimate the summary effectiveness of different needle-stick injury (NSI)-prevention interventions.DESIGNWe conducted a meta-analysis of English-language articles evaluating methods for reducing needle stick, sharp, or percutaneous injuries published from 2002 to 2012 identified using PubMed and Medline EBSCO databases. Data were extracted using a standardized instrument. Random effects models were used to estimate the summary effectiveness of 3 interventions: training alone, safety-engineered devices (SEDs) alone, and the combination of training and SEDs.SETTINGHealthcare facilities, mainly hospitalsPARTICIPANTSHealthcare workers including physicians, midwives, and nursesRESULTSFrom an initial pool of 250 potentially relevant studies, 17 studies met our inclusion criteria. Six eligible studies evaluated the effectiveness of training interventions, and the summary effect of the training intervention was 0.66 (95% CI, 0.50–0.89). The summary effect across the 5 studies that assessed the efficacy of SEDs was 0.51 (95% CI, 0.40–0.64). A total of 8 studies evaluated the effectiveness of training plus SEDs, with a summary effect of 0.38 (95% CI, 0.28–0.50).CONCLUSIONTraining combined with SEDs can substantially reduce the risk of NSIs.Infect Control Hosp Epidemiol2015;36(7):823–829

Over the last decade, sustainability science has been at the leading edge of widespread efforts from the social and natural sciences to produce use-inspired research. Yet, how knowledge generated by sustainability science and allied fields will contribute to transitions toward sustainability remains a critical theoretical and empirical question for basic and applied research. This article explores the limitations of sustainability science research to move the field beyond the analysis of problems in coupled systems to interrogate the social, political and technological dimensions of linking knowledge and action. Over the next decade, sustainability science can strengthen its empirical, theoretical and practical contributions by developing along four research pathways focused on the role of values in science and decision-making for sustainability: how communities at various scales envision and pursue sustainable futures; how socio-technical change can be fostered at multiple scales; the promotion of social and institutional learning for sustainable development.

Objective.Sharps with engineered sharps injury protections (SESIPs) have been found to reduce risk of sharps injuries (Sis). We examined trends in SI rates among employees of acute care hospitals in Massachusetts, including the impact of SESIPs on SI trends during 2002-2007.Design.Prospective surveillance.Setting.Seventy-six acute care hospitals licensed by the Massachusetts Department of Public Health.Participants.Employees of acute care hospitals who reported Sis to their employers.Methods.Data on Sis in acute care hospitals collected by the Massachusetts Sharps Injury Surveillance System were used to examine trends in SI rates over time by occupation, hospital size, and device. Negative binomial regression was used to assess trends.Results.During 2002-2007, 16,158 Sis among employees of 76 acute care hospitals were reported to the surveillance system. The annual SI rate decreased by 22%, with an annual decline of 4.7% (P< .001). Rates declined significantly among nurses (—7.2% per year; P< .001) but not among physicians (—0.9% per year; P= .553). SI rates associated with winged steel needles and hypodermic needles and syringes also declined significantly as the proportion of injuries involving devices with sharps injury prevention features increased during the same time period.Conclusion.SI rates involving devices for which SESIPs are widely available and appear to be increasingly used have declined. The continued use of devices lacking SI protections for which SESIPs are available needs to be addressed. The extent to which injuries involving SESIPs are due to flaws in design or lack of experience and training must be examined.

Home health care (HHC) is growing rapidly and yet health and safety conditions of HHC clinicians are poorly understood. Study of this workforce presents unique challenges because it is decentralised, often part-time and mobile. As part of a larger project on sharps injuries and blood exposures in HHC, this paper addresses the challenges of recruiting a large cohort of HHC nurses and aides and describes novel cross-sectional survey methodology. Recruitment was conducted with cooperation from eight HHC agencies and two labour unions. Intensive personal contacts and a financial incentive ($25) were employed. Some groups of HHC clinicians could be contacted only by mail, while others were contacted during a promotional “mini-fair” at their agency. A total of 1772, 18-page health and safety surveys were distributed and 1225 usable surveys were collected. This 69% overall response rate is better than that in many recent health surveys. Survey returns were highest (67—91%) where promotional events were held. The mailing-only strategy generated lower response rates (53—55%), despite the same financial incentive. Despite the challenges of reaching out to the decentralised HHC workforce, adequate response to a detailed health survey is possible, using appropriate techniques and with the close cooperation of employers and labour unions.

To examine the association between intelligence quotient (IQ) measured at ages 18 to 20 and onset of smoking, and the association between IQ and smoking cessation.

Construction workers performing drywall installation are exposed to a variety of ergonomic hazards, including heavy material handling, repetitive motions and awkward postures. The rates of musculoskeletal injuries and disorders among drywall installers are very high, especially at the low back and shoulder. The unique characteristics of the work environment in the construction industry do not allow for applying objective ergonomic assessment instruments. Thus, biomechanical models and computer simulations were combined for a more comprehensive evaluation of ergonomic hazards. Utilizing Monte-Carlo simulation to generate the input for biomechanical models based on information from PATH (Posture, Activity, Tools, and Handling), a work-sampling based approach, the present study estimated the required muscle contraction forces and joint reaction forces at the low back and shoulder during a simulated 8-hour drywall installation workday. The results of this study also provided a database for future evaluations of ergonomic interventions on drywall installation work.

A number of studies have shown possible associations between occupational exposures, particularly solvents, and lymphomas. The present investigation aimed to evaluate the association between exposure to solvents and lymphomas (Hodgkin and non-Hodgkin) in a large population-based, multicenter, case–control study in Italy.

The objectives of this study were to document the high rates of acute injuries and physical assaults among nurses and certified nursing assistants working in long-term psychiatric care facilities and to identify risk factors for assaults and injuries to inform prevention strategies. A mixed-design cohort study was conducted. Acute injury and physical assault data were obtained from administrative records. Using staff rosters and schedule records, incidence rates were calculated by job title, gender, shift, and floor. Rates were also reported by severity, body part, type, and nature. Targeted interviews with staff members provided measures of physical lifting and resident combativeness. Injury rates were calculated by degree of lifting and assault rates were calculated by degree of resident combativeness. Overall rates of injuries (55.6 per 100 person-years) and assaults (67.3 per 100 person-years) were substantially higher than expected. Predictably, injuries were associated with resident lifting and assaults were associated with contact with combative residents. A higher risk of assault was found among women and higher risks of injury and assault were observed among full-time employees compared to per diem or pool agency workers. In addition, weekend shifts were found to have a higher rate of injuries and a lower rate of assaults than weekday shifts. In similar longterm care facilities with psychiatric populations, efforts should be made to reduce lifting and avoid circumstances that agitate residents. Work organization factors should be taken into consideration when developing interventions.

Exposure to metalworking fluids has been previously associated with prostate cancer mortality in a cohort of autoworkers. Our objective was to further explore this finding in a study of prostate cancer incidence in the same cohort, with reduced misclassification of outcome.

Abstract Objective: Prostate cancer is hormone-related and chemicals that interfere with hormones may contribute to carcinogenesis. In a cohort of autoworkers we characterized exposure to metalworking fluids (MWF) into age windows with homogenous biological risk for prostate cancer, and examined exposure–response relationships using semi-parametric modeling.

Several studies have shown a relation between smoking and suicide. It is not clear if this relation should be considered causal, or if other risk factors for suicide, left unmeasured in many studies, might explain the smoking-suicide association. The aim of this cohort study was to analyse the role of smoking and other potential risk factors measured in adolescence on subsequent suicide.

Objective: Meta-analysis was used to summarize the published evidence on the associations between alcohol and tobacco consumption and cancers of the oropharynx, pharynx, larynx, and esophagus. The objective was to produce summary risk estimates with uniform methods and on uniform exposure scales so that the magnitudes of the risks could be compared across tumor sites. Methods: Epidemiologic studies that estimated the effects of alcohol and tobacco consumption on the risk of cancers of the upper aero-digestive tract were identified from the MEDLINE database, 1966–2001. Alcohol and tobacco data were converted into common units (grams/week). For all studies meeting eligibility criteria, effect parameters (slopes) were estimated for both exposures. The exposure-risk slopes for each study were combined, site by site, using random effects meta-regression methods. Results: Fourteen studies met the final selection criteria. The carcinogenic effects of alcohol and tobacco were found to be multiplicative on the relative risk scale. Tobacco appeared to have a much stronger effect on the larynx than on any of the other aerodigestive sites, while alcohol's effect was strongest on the pharynx. The weakest association was that of alcohol and adenocarcinoma of the esophagus – an order of magnitude weaker than that for tobacco and laryngeal cancer. Conclusions: Meta-analysis was used to combine the results from all available studies, providing a comprehensive summary of the combined effects of alcohol and tobacco on the upper aerodigestive cancers.

We conducted a population-based, case-control study on hematolymphopoietic malignancies in 12 areas in Italy to investigate associations between different hematolymphopoietic malignancies and exposure to solvents and pesticides. We collected all incident cases 20–74 years of age from 12 areas, with a combined population of approximately 7 million residents. The control group was formed by a random sample of the study population. Data presented in this paper refer to 2,737 interviewed cases of 3,357 eligible cases and to 1,779 of 2,391 eligible controls. We analyzed risks associated with occupation using job-title information to evaluate disease pattern according to job category. An earlier publication presented results for women; here, we report the findings for men and discuss the overall patterns in both genders. The most consistent overall finding was an approximate doubling in relative risk for all four types of malignancies among male managers and related occupations. Several additional occupations were associated with elevated risk of one or more malignancies among men. These included cooks, waiters, and bartenders, and building caretakers and cleaners, for non-Hodgkin’s lymphoma; textile workers and machinery fitters for Hodgkin’s lymphoma; metal processors, material handlers, rubber workers, and painters for leukemia; and hairdressers, metal processors, tailors, electrical workers, and plumbers for multiple myeloma. The finding of increased risk of non-Hodgkin’s lymphoma among both male and female cooks, waiters, and bartenders has not been previously reported; nor has the elevated risk of leukemia among material handlers. Among people engaged in agriculture, those employed as tractor drivers and as “orchard, vineyard, and related tree and shrub workers” appeared to be at increased risk for hematolymphopoietic malignancies.

Exposure assessment was conducted for an epidemiologic study of the respiratory effects of exposure to metalworking fluids (MWF). As part of the study, airborne microorganisms were collected with a two-stage microbial impactor, and a sample of the bulk soluble MWF was collected from each machine sump, as well as information about the work environment. These data were then used to develop multivariate statistical models of the determinants bulk MWF and airborne microbial levels. Microbial concentrations in the bulk MWF ranged from 5×104 to 5×1010 colony-forming units (CFU)/mL, with a geometric mean of 3.4×107 CFU/mL. The geometric mean airborne microbial level was 182 CFU/m3 (for particles size <8 µm) with a range of 1 to 8308 CFU/m3. In modeling the determinants of bulk microorganisms, fluid-related factors were the most important characteristics associated with microbial levels, followed by process-related and environmental factors. The final full multivariate model predicted a significant reduction in bulk microbial levels by increasing pH of the fluid and reducing the amount of tramp oil leaking into the fluid. For the airborne microbial models, process-related factors were the major characteristics associated with microbial levels, followed by factors related to worker activities and environmental factors. The final full multivariate model predicted a significant control of airborne microorganisms by increasing worker distance from the machine, reducing the number of machines within 10 feet of the worker, decreasing the bulk microbial levels, and adding machine enclosures. These models can be used to prioritize nonbiocidal interventions to control microbial contamination of the bulk MWF and the air.

BackgroundIn the future, competitive industries will need to design for environment, health and safety as well as for productivity. Although the new areas of pollution prevention and clean production have evolved to address the design of production processes with concerns for the ambient environment, current pollution prevention models do not include explicit concerns for health, safety, and the work environment. The field of occupational health and safety has much to contribute to improve current pollution prevention approaches and solutions.

This study examines the determinants of susceptibility to the irritant effects of sodium borate in 18 responsive workers identified through repeated self‐reports of nasal irritation. For each worker, susceptibility was characterized by two features; reactivity and sensitivity, as estimated from the slope and intercept parameters from their individual exposure‐response regression model. Individual estimates of reactivity and sensitivity were then examined to evaluate the importance of personal and environmental characteristics in determining susceptibility. The use of nasal sprays, current smoking and allergies were associated with lower reactivity, while high exposures to borate dust were associated with higher sensitivity. To examine possible biologic mechanisms for the irritant response, a toxicokinetic dose model was used to calculate nasal osmolarity during symptom intervals. The estimated levels suggest that osmolar activation of mast cells to release histamine and other mediators is a plausible mechanism by which these workers may experience nasal irritation. Am. J. Ind. Med. 34:614–622, 1998. © 1998 Wiley‐Liss, Inc.

Previous investigations of cancer among firefighters have been limited to mortality data and have yielded inconsistent results. Case‐control analyses were conducted in the present surveillance study in order to examine associations between firefighting and cancer incidence in Massachusetts. Subjects were identified through the Massachusetts Cancer Registry files for 1982–1986. Exposure status (firefighting) was determined from the usual occupation reported to the Registry. Nine different cancer types were examined among the 315 reported white male firefighters. Two “unexposed” reference populations were used: policemen and statewide males. Standardized morbidity odds ratios (SMORs) were statistically significantly elevated for melanoma (SMOR = 292; 95% C.I. = 170–503) and bladder cancer (SMOR = 159; 95% C.I. = 102–250) among firefighters compared with the state as a whole. When policemen were used as the reference group, the bladder cancer excess persisted (SMOR = 211; 95% C.I. = 107–414) and non‐Hodgkin's lymphoma was elevated (SMOR = 327; 95% C.I. = 119–898); the melanoma excess was largely reduced (SMOR = 138; 95% C.I. = 60–319) but remained elevated among those aged 55–74 years (SMOR = 513;95%C.I. = 150–1,750). Small number excesses (not significant) were also observed for pancreatic cancer and leukemia compared with police.

A short‐term follow‐up study was performed on 55 workers in a gear plant exposed to PCB that contaminated the work surfaces. Current work did not involve the use of PCBs. Exposure was to residual PCB left behind by a capacitor company which formerly used the site. Elevated PCB levels were found in production area workers; these elevations persisted on retesting 1 year later. Efforts should be made to identify potentially toxic materials left behind on work surfaces of buildings before remodeling or reuse.

BackgroundResults are reported from a nested case‐control study of 60 esophageal cancer deaths among 46,384 automobile manufacturing workers potentially exposed to metalworking fluids (MWF) in machining and grinding operations.

A study of cross‐shift change in pulmonary function was conducted among workers exposed to metal working fluids (MWF) in an automobile parts manufacturing company. Three hundred eighty‐six workers (216 machinists exposed to straight or soluble MWFs, and 170 nonmachinists) were studied for 1 day, performing spirometry at the beginning and end of their shift. Airborne concentrations of inhalable particulate, culturable bacteria, and endotoxin were measured. We observed an approximately threefold increase in the incidence of 5% or greater cross‐shift decrement in forced expiratory volume during the first second among those with exposures above about 0.15 mg/m3, compared to those with exposures below about 0.08 mg/m3. There was some evidence that chronic respiratory symptoms were more prevalent among machinists than among nonmachinists, notably for chronic cough. Baseline FEV1was about 3% lower on average among those with soluble MWF exposure compared to nonmachinists. These findings are consistent with earlier studies showing respiratory effects of MWFs. Am. J. Ind. Med. 31:756–766, 1997. © 1997 Wiley‐Liss, Inc.

An investigation of the acute respiratory effects of workers exposed to metal working fluids (MWF) was conducted in an automobile parts manufacturing facility. After observing an association between cross‐shift decline in forced expiratory volume in the first second (FEV1) and aerosol mass concentration, improved characterization of the exposure was sought through investigation of four elements of a priori interest (Cl, Cr, Ni, S). Of these, only sulfur showed an association with cross‐shift FEV1decrement. The relative risk of 5% cross‐shift FEV1decrement was 2.7 (95% confidence interval = 1.0–6.0) comparing those with >4.4 μg/m3to those with <2.5 μg/m3sulfur exposure. Because the concentrations of sulfur in this environment were relatively low and other respiratory irritants were present, sulfur is more likely to be an indicator of more irritating conditions than the sole agent responsible for the observed acute respiratory effects. Am. J. Ind. Med. 31:767–776, 1997. © 1997 Wiley‐Liss, Inc.

The current metal-working fluid exposures at three locations that manufacture automotive parts were assessed in conjunction with epidemiological studies of the mortality and respiratory morbidity experiences of workers at these plants. A rationale is presented for selecting and characterizing epidemiologic exposure groups in this environment. More than 475 full-shift personal aerosol samples were taken using a two-stage personal cascade impactor with median size cut-offs of 9.8 µm and 3.5 µm, plus a backup filter. For a sample of 403 workers exposed to aerosols of machining or grinding fluids, the mean total exposure was 706 µg/m3 (standard error (SE)=21 µg/m3). Among 72 assemblers unexposed to machining fluids, the mean total exposure was 187±10 (SE)µg/m3. An analysis of variance model identified factors significantly associated with exposure level and permitted estimates of exposure for workers in the unsampled machine type/metal-working fluid groups. Comparison of the results obtained from personal impactor samples with predictions from an aerosol-deposition model for the human respiratory tract showed high correlation. However, the amount collected on the impactor stage underestimates extrathoracic deposition and overestimates tracheobronchial and alveolar deposition, as calculated by the deposition model. When both the impactor concentration and the deposition-model concentration were used to estimate cumulative thoracic concentrations for the worklives of a subset of auto workers, there was no significant difference in the rank order of the subjects' cumulative concentration. However, the cumulative impactor concentration values were significantly higher than the cumulative deposition-model concentration values for the subjects.

The exposure assessment summarized here is part of an epidemiologic study of the acute respiratory health effects of metalworking fluid (MF) exposures. Exposures were measured as the inhalable concentrations of the MF aerosol, a variety of metals and elements, and endotoxin as well as the level of culturable bacteria in the aerosol size fraction less than 8 µm. Bulk samples of soluble MFs were tested for pH, mineral and tramp oil fraction, endotoxin, culturable bacteria, and lipopolysaccharide levels. The MF exposed workers had higher geometric mean inhalable aerosol exposures (0.181 mg/m3) than the MF unexposed workers (0.046 mg/m3). The MF exposed workers had higher geometric mean (GM) airborne culturable microbial counts (102 colony-forming units (CFU)/m3 for bacteria <8 µm) than the unexposed workers (GM=14 CFU/m3). Among the unexposed, Bacillus was the predominant airborne species, while among the exposed workers, Pseudomonas predominated. Exposed workers also had higher geometric mean airborne endotoxin levels (GM=7.1 endotoxin units (EU)/m3) than the unexposed workers (GM=1.9 EU/m3). Elemental concentrations of iron, chlorine, and sulfur were substantially higher among the exposed workers compared to the unexposed workers. For soluble metalworking fluids, the levels of bulk constituents were examined by three categories of time since the machine sump was refilled with fresh MF (<4 days, 4-21 days, >21 days). Univariate analyses of percent oil, pH, culturable bacteria, tramp oil percent, endotoxin, or fatty acid levels all showed no statistically significant changes in level over time.

Personal monitoring of extremely low frequency magnetic fields was conducted at a large automatic transmission plant for a case-control study of primary brain cancer. Current workers were selected to represent the jobs most commonly held by study subjects. Several exposure indices, corresponding to different plausible biological mechanisms, were computed for each of 81 workers who wore the monitoring instrument for one-half shift. Average exposures covered a range from 0.16 to 46 mG; median exposure was 1.3 mG. Nonparametric correlations were estimated to learn whether all of these indices rise and fall together. Results were mixed, in that indices sensitive to high values showed correlations above 0.7, but other correlations were between 0.4 and 0.6. Different indices may thus identify different groups as “highly” exposed. The authors also tested whether indices based on the fraction of time spent above hypothesized thresholds were accurately predicted by a lognormal model. For 47% of the workers, the observed indices significantly exceeded those predicted by such a model, suggesting that lognormality is not a good model for distributions of individuals' short-term exposures.

The proportion of residents born in northern Europe best explains the pattern of stomach cancer mortality in Minnesota, Wisconsin, and upper Michigan counties. The settling patterns of Finns, and to a lesser extent of Poles, Norwegians, Danes and Swedes, are strongly associated with county stomach cancer rates. Socio-economic status and water supply are less significant. Even after socioeconomic status and water supply are factored out, estimated stomach cancer mortality for these populations is still disproportionately high. Other researchers have identified diet as a major risk factor in stomach cancer and as the prime cause of the ethnicity-stomach cancer association. We suggest that natives shared the stomach cancer risk, perhaps by adopting the “high risk”; diet of the foreign-born.