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The seasonal rise in fat and cholesterol intake during the winter identified in 94 male employees at two factories in Israel is linked with changes in body mass index (BMI) and serum cholesterol. The largest seasonal change in biochemical measurements was in serum LDL, raised levels of which are known to increase the long-term risk of developing coronary heart disease. It is clear that there is a need to modify the diet of industrial employees, possibly through interventions in the workplace.

Some 6,016 employees in 21 Israeli industrial plants were studied to examine the association between indoor temperature control (TC) at the workplace and working heart rates (HR) of industrial workers. The resting HR, working HR, workload, age and health-related habits of the subjects were collected, as well as the outdoor temperatures and the TC status of the plants. Although no significant difference was noted in the mean working HR of subjects working with TC and those without TC in the outdoor temperature range, the study suggests that indoor temperature control in plants moderates the cardiovascular strain in working subjects during cold and hot days.

The objective of this study was to evaluate the association of physical activity at work with the risk of all-cause cardiovascular disease and cancer mortality. The cohort consisted of 3488 male, Israeli, industrial employees who participated in an 8-year follow-up study. During this period 129 deaths were recorded: 54 from cardiovascular disease, 47 from cancer, and 28 from other causes. Physical activity at work was assessed at entry on a 4-point scale (none, light, medium, and high). Potential confounding demographic, anthropometric, and socioeconomic variables, and health habits including leisure time physical activity were accounted for. We found that the hazard ratio of all-cause mortality in workers with a high physical workload was 1.82 (95% confidence interval, 1.18 to 2.81) compared with workers having a low workload. A similar trend was noted for cardiovascular disease and cancer mortality. We concluded that a high physical workload is associated with increased mortality rates. Future studies should differentiate between leisure time and work time physical activity. [ABSTRACT FROM AUTHOR]

Studies the increased serum concentrations of secreted growth factors receptors in workers exposed to asbestos in the past but without asbestos related disease. Role of epidermal growth factor receptor (EGFR) and oncogene Neu in carcinogenesis; Findings of enhanced secretion of EGFR and Neu in a large cohort of a retired asbestos workers; Determination of the source of the secreted growth factor receptors.

Objective: To clarify whether somatic complaints in healthy normotensive men are associated with differential 24-hour blood pressure and heart rate measures.Method: Twenty-four-hour ambulatory systolic and diastolic blood pressure was monitored in 114 healthy normotensive men, aged 28 to 63 years, engaged in similar physical work. Means were calculated for each hour, for the whole 24-hour period, and for daytime, nighttime, and work time. Subjects were interviewed about somatic complaints, demographic data, and health habits, and body mass index was measured.Results: After controlling for possible confounders, a positive association was found between the somatic complaint score and 24-hour, diurnal, and work-time systolic blood pressure (p = .014, p = .007, and p = .008, respectively). The association with casual systolic blood pressure was of borderline significance (p = .089). There was a positive trend, which did not reach statistical significance, in the relationship between somatic complaint score and all measures of diastolic blood pressure. Diurnal, 24-hour, and work-time heart rates were highest in the subjects with the highest somatic scores (p < .01 for all trends).Conclusions: In healthy normotensive men, somatic complaints are associated with an increased cardiovascular load. The effects of this increase on long-term cardiovascular morbidity and mortality are uncertain and warrant additional study. [ABSTRACT FROM AUTHOR]

Objectives: The accident rate might be influenced by intrinsic characteristics of the workers, by risks inherent in the work environment, or a combination of these factors. As increased weight may be associated with sleep disturbances and fatigue, a high body mass index (BMI) might be an independent risk factor for accidents in industrial workers.Methods: 3801 men were examined and followed up for two years for the occurrence of accidents. The objective environmental conditions were recorded and translated into a single score of ergonomic stress levels. Height and weight were recorded, as were possible confounding factors including measures of fatigue, type A personality, total night time sleep, job satisfaction, somatic complaints, smoking, and education levels.Results: Both BMI and ergonomic stress levels independently predicted involvement in accidents (two or more) with those in the highest BMI quartile who worked in an environment with high ergonomic stress levels having a 4-6 times increased risk of accidents compared with those in the lowest BMI quartile who worked in an environment with low ergonomic stress levels (95% confidence interval (95% CI) 2.4-9.0, P < 0.001). Although increasing somatic complaints and a low educational level also were predictors of accidents, they did not mediate the effect of the BMI on the accident rate. Increasing age, less smoking, and decreased sleep hours were significantly associated with an increased BMI, but the association of BMI and involvement in accidents also could not be explained by those factors or the other confounders.Conclusions: BMI independently influences the accident rate. Further studies warranted to confirm these findings and to explore mechanisms supporting biological plausibility. [ABSTRACT FROM AUTHOR]

Inorganic lead (Pb) is a ubiquitous environmental contaminant that produces a variety of deleterious effects in the central nervous system (CNS). Matrix metalloproteinases (MMPs), specifically MMP-9, induced by inflammatory cytokines, are increasingly being implicated in CNS pathology. The present study demonstrates that low concentrations of either pro-inflammatory cytokines (TNF-alpha and IL-1beta) or Pb did not influence the MMP-9 expression in a glial cell line (C6) when added separately. However, combined administration of Pb and cytokines induced a marked synergized elevation of MMP-9 expression in spite of a reduction in the number of glial cells. These results demonstrate a possible new mechanism by which Pb may induce neuropathological processes.

Background: The degree to which serum total cholesterol predicts cardiovascular disease is uncertain. While most authors have placed TC among the most powerful risk indicators of CVD, some have claimed that it predicted CVD in women only, or even not at all., Objective: To determine the predictive value of serum total cholesterol relative to diabetes, smoking, systolic blood pressure and body mass index (kg/m2), for cardiovascular disease mortality in 3,461 occupationally active Israeli males., Methods: A prospective follow-up was carried out for the years 1987-1998 to determine the effect of age, smoking habits, a history of diabetes, SBP, BMI and TC, at entry, on CVD mortality., Results: There were 84 CVD deaths during a total of 37,174 person-years follow up. The hazard ratios (95% confidence intervals) for CVD mortality with respect to variables at entry were: diabetes 5.2 (2.1-13.2), age 2.2 (1.7-2.9), smoking 1.3 (1.0-1.8), SBP 1.4 (1.1-2.0), TC 1.5 (1.0-2.1) and BMI 1.2 (0.7-2.2). Among non-obese, non-diabetic, normotensive subjects the hazard ratio of TC adjusted for age and smoking was 1.16 (1.09-1.22) per 10 mg/dl. In the remaining subjects it was 1.04 (0.98-1.12) only. There was a significant interaction between TC and diabetes, hypertension or obesity (P = 0.003)., Conclusions: In this population of Israeli males we found an interaction between TC and other risk indicators for CVD. Confirmation is required for the unexpected finding that the predictive value of TC for CVD mortality among non-diabetic, non-obese and normotensive subjects exceeded that among subjects with either of these risk factors.

Objective: To examine possible seasonal changes in heart rate variability (HRV)., Background: Greater than normal mortality from cardiovascular disease (CVD) in the winter has been reported for many countries and might be partly explained by considering seasonal changes in CVD risk factors. Depression of HRV is an independent predictor of arrhythmic complications and of cardiac death, and it is also among the variables that may be affected by the season of the year., Methods: We compared pairs of 24 h HRV data of 120 healthy men who were examined once in the summer and once in the winter. Multivariate analyses were performed for each dependent variable (HRV indexes) in separate statistical models with age, resting heart rate, serum level of cholesterol, cigarette smoking, body mass index, sports habits, alcohol consumption, systolic blood pressure, physical activity at work, years of education, consumption of energy, and season as the independent variables., Results: Although there were no seasonal differences in mean R-R interval, all indexes of HRV were found to be lower in the summer than they were during winter. Differences and 95% confidence intervals were standard deviation (SD) of coupling intervals between normal beats 12 ms, 6-17 ms; SD of 5 min mean R-R intervals 14 ms, 8-20 ms; mean of all 5 min SD of R-R intervals 2.0 ms, 0.6-2.5 ms; proportion of adjacent R-R intervals differing by > 50 ms 1.5%, 0.6-2.5% and root mean square of the difference between successive normal intervals 3.1 ms, 1.5-4 ms. Multivariate analyses showed that HRV in the winter was less than that in the summer even after adjustment for age, serum level of cholesterol, systolic blood pressure, and body mass index., Conclusions: HRV indexes of healthy men vary physiologically by season, with lowest values obtained in the winter. Since low HRV is linked to pathologic conditions, the significance of seasonal changes for those suffering from CVD and their possible contribution to the greater mortality rates in winter have to be considered.

Rehabilitation after acute myocardial infarction (AMI) consists of education, exercise, and an encouragement to return to work (RTW). This study attempts to (1) determine whether the time interval between AMI and the visit at occupational medicine (OM) clinics predicts resumption of full employment, and (2) estimate the incidence of work-related recurrent AMI after RTW. We followed 216 consecutive AMI patients at a single OM clinic. The independent variables were clinical and personal data, physical workload and time between AMI, and first visit to the OM clinic. The outcome variables were full employment 24 months after the acute event and recurrent AMI during this period. Of all patients, 168 attempted RTW. Of these, 18 stopped working subsequently. Of the remaining 150 patients, 54 returned to part-time work and 96 were employed full-time after 2 years. Logistic regression indicated that a failure to resume full employment was independently associated with diabetes, older age, Q wave AMI, angina before AMI, heavy work, and a late visit to the OM clinic. For each month's delay in referral to the OM clinic, there was a 30% decrease in the chance for full employment 24 months after AMI. Six (4%) of the 150 patients who resumed employment sustained a recurrent AMI, two of them while at work. A delayed referral to the OM clinic was associated with work disability after AMI. Late referrals to OM clinics should receive a more intensive and sustained rehabilitation than early referrals. Whether an earlier referral to OM clinics will result in increased RTW rates is unknown. Patients who attempted to resume employment had a 1.2% risk of a recurrent ischemic event at their workplace.

The objectives of the study were to compare dietary intake by smoking levels in blue-collar Israeli workers occupationally exposed to lead and thus identify additional areas for health-enhancing intervention in addition to smoking cessation. One hundred and eighty-seven male industrial employees who were exposed to lead through their work were screened at the worksite to evaluate health status and dietary intake. Smokers had higher intakes of fat, cholesterol, calcium, riboflavin, and vitamin E per day. They were consuming more meat and high-fat dairy products. Dose-response relationships were shown for fat and energy intake by smoking level. Thus, smoking is associated with other adverse health behaviors. When conducting epidemiologic or occupational studies, analyses should include adjustment for the fact that the lifestyles of smokers may also be unhealthy in other ways.

Seasonal changes in calcitropic hormones might be expected, being that dietary calcium intake may differ with fluctuations in climate and temperature, and vitamin D is diet- and sunlight-dependent. While there are studies on elderly subjects, prospective data on younger men is limited. The objective of this study was to clarify possible seasonal changes in homeostatic regulators of calcium in Israeli men aged 25-64 years. The study was a prospective follow-up analysis of data collected during June-August 1995 and 1996 (summer) and January March 1995 and 1996 (winter). Subjects were ninety-five industrial male employees with and without occupational lead exposure. The main outcome measures were summer and winter serum concentrations of parathyroid hormone (PTH), 25-hydroxyvitamin D (25-OH-D), and 1,25-dihydroxyvitamin D (calcitriol). Summer and winter values of PTH were similar (38.2 and 39.8 ng/l, respectively). 25-OH-D levels were significantly higher in summer (32.8 ng/ml) than in winter (25.4 ng/ml) after controlling for possible confounders (p < 0.0001). Calcitriol levels were significantly higher in summer (79.1 pmol/l) than in winter (73.5 pmol/l) in univariate analyses, but not after controlling for possible confounders. We conclude that healthy men show considerable seasonal changes in 25-OH-D levels even in Israel, a relatively sunny country all the year round. Summer values of 25-OH-D, were 35% higher than in winter. These fluctuations should be taken into account during evaluation of pathological conditions and in research. Given an adequate diet and vitamin D status there are no seasonal variations in PTH or in calcitriol levels.

Anemia is a manifestation of lead toxicity. However, there are conflicting reports of its prevalence among lead-exposed workers, and it is uncertain whether they should be monitored by periodic hemoglobin (Hb) examinations. To explore the relationship between Hb and lead exposure, we examined the correlation between Hb, blood lead (PbB), and zinc protoporphyrin (ZPP) levels in 961 blood samples obtained from 94 workers in a lead-acid battery plant in Israel between 1980 and 1993. Blood lead levels exceeded 60 micrograms/dL (2.90 mumol/L) in 105 (14%) of the blood samples. The correlation between PbB and logZPP was 0.594. Hb levels did not correlate with PbB or ZPP. We conclude that (a) periodic Hb determinations are not a useful indicator of lead exposure in Israeli industrial workers; (b) the discrepancies between the reported correlation between PbB and Hb levels remain unexplained and in need of further study; and (c) a finding of anemia in a person with PbB levels of up to 80 micrograms/dL should be considered to be due to lead toxicity only after other causes for anemia have been excluded.

Previous studies of the association between occupational noise exposure and cardiovascular disease (CVD) or risk factors for CVD are primarily either cross-sectional or retrospective, whereas the design of the CORDIS study was both cross-sectional and longitudinal. It had three phases: Phase I was conducted during 1985-87 among 6,016 employees from 21 factories. Recorded were medical, ergonomic, environmental (including noise levels at the various work stations) and psychological data. Phase II was conducted during 1988-90, at 18 of the 21 original factories and included similar data collected from 3,509 subjects. Phase III was conducted during the years 1995-96 and 4,995 workers who participated in Phases I and II completed questionnaires pertaining to medical, occupational and life style variables. Mortality and cancer morbidity data were obtained over an 8 year follow-up period for all subjects. Results from Phase I, revealed no association between noise exposure and resting blood pressure. Positive association was found for serum lipids in women and in young men. Noise annoyance had an additive effect on this outcome. In addition, recurrent daily noise exposure was found to be associated with elevated acute resting heart rate. Results of Phase II showed that chronic exposure to high noise levels during the 2-4 years of the follow-up resulted in changes of 3.9 mmHg in SBP and 3.3 mmHg in DBP, among workers performing complex jobs. In workers performing simple jobs these changes were 0.3 and 0.4 mmHg. Thus the type of work performed appears to be a significant factor. Results of Phase III revealed that there was a trend for positive association between past noise exposure measured at Phase I and 8 years incidence of cardiovascular morbidity, mortality and total mortality. This trend was statistically significant for total mortality (hazard ratio = 1.97, 95% CI 1.28-4.54) even after controlling for possible confounders. In summary, tests for association between noise exposure and cardiovascular risk factors, or cardiovascular morbidity and mortality, and total mortality have yielded mixed results. Reasons for this are discussed, as well as suggestions for further research.

Workers exposed to lead may benefit from a calcium-rich diet, since calcium competes with lead for intestinal absorption. We studied the effect of dietary calcium on blood lead levels. We assessed blood lead levels, dietary intake of calcium, smoking and alcohol consumption, and anthropometric and demographic data in 56 workers exposed to lead and 90 workers without such exposure. Mean intake of dietary calcium was 775 +/- 370 mg/day in the nonexposed workers and 858 +/- 423 mg/day in the exposed workers. Occupational lead exposure explained nearly 90% of the variance in blood lead levels of the entire cohort. Smoking and alcohol intake also showed significant associations with blood lead levels, but their combined effect was less than 2%. When the exposed and nonexposed workers were considered separately, no association was found between blood lead levels and calcium intake. The amount of calcium in the diet does not influence blood lead levels. Further studies are warranted to determine whether dietary calcium influences blood lead levels in exposed and nonexposed workers in other settings and in subjects with lower intakes of calcium.

Background: The objective of this study was to determine the effects of teaching the scooping-resheathing method on the incidence of needle-stick injuries in medical students., Methods: Before starting their first clerkship, 81 medical students were given a 15-min lecture on the high incidence and dangers of needle-stick injuries and a demonstration of the scooping-resheathing method. The number of needle-stick injuries that occurred during the 3-month clerkship was compared with the number reported by 86 medical students who had completed their first clerkship 1 year previously and had not been given such instruction., Results: Compared with controls, the study group had a 3.8-fold lower risk of needle-stick injury (95% confidence interval, 2.0-7.4, P < 0.0001) and a 8.3-fold lower risk of multiple needle-stick injuries (95% confidence interval, 2.0-35.0, P < 0.001). Those in the study group, who consistently used the scooping method had a much lower risk of injury than those who did not (1 of 36 [2.8%] vs. 8 of 45 [17.4%], P = 0.039)., Conclusions: We conclude that a lecture recommending the scooping-resheathing method is effective in reducing the risk of needle-stick injuries in medical students during their first rotation. Because this is the first time that an intervention not requiring change in equipment has been successful, further studies are warranted to substantiate our findings and for extrapolation to other medical personnel in other cultural settings.

Blood lead (PbB) and red cell zinc protoporphyrin (ZPP) concentrations are widely used biomarkers for lead toxicity. It is uncertain, however, whether either or both are needed for monitoring lead exposure and how discordant PbB and ZPP values should be interpreted. We reviewed the results of PbB and ZPP determinations in 94 workers in a lead-battery plant over a 13-year period and retrieved all 807 sets of tests in which both PbB and ZPP were available, with a follow-up PbB value 6 months later. PbB exceeded 1.93 micromol/L (40 microg/dL) in 414 (51%), and 2.90 micromol/L (60 microg/dL) in 105 (14%) of the blood samples. We derived the test properties of various ZPP concentrations for concurrent "toxic" PbB concentrations, defined as > or = 1.93 and 2.90 micromol/L (40 and 60 microg/dL). The results indicated that, given a population of lead-exposed workers with a 10% prevalence of PbB of > or = 2.90 micromol/L (60 microg/dL), a policy of testing PbB only in those with ZPP > 0.71 micromol/L (40 microg/dL) would obviate 42% of the PbB tests, but would miss about three cases with toxic PbB concentrations in every 200 workers at risk. A finding of increased ZPP concentrations with a concurrent "nontoxic" PbB was associated with an increased risk of a toxic PbB concentration 6 months later. We conclude that (a) screening by testing only ZPP does not safeguard exposed persons against lead toxicity, and (b) the frequency of PbB monitoring should be guided by estimates of the risk of future lead toxicity in individual workers.

In the following study, we examined the possible relationship between acute and chronic measures of lead exposure and total white cell blood counts in 94 workers in a lead-battery plant who were followed-up from 1980 to 1993. Acute measures of lead exposure included blood lead (PbB), and zinc protoporphyrin levels (ZPP) measured concomitantly with the total white blood count, and a measure of chronic exposure was represented by average blood lead levels over the follow-up period. Of the 947 white blood cell counts, leukocytosis was found in 92 (9.7%), but there was no higher proportion of leukocytosis in the groups with higher PbB or ZPP results. Of those where a smoking history was recorded, none of the 188 non-smokers had leukocytosis, compared to 78 of 590 smokers (0 vs. 13.2%, respectively, P < 0.05). The white count was not significantly correlated with ZPP, PbB or the average PbB of the workers. We conclude that lead exposure does not influence the white blood cell count in battery workers, and that the cause of an elevated white count in such worker's is probably due entirely to a history of smoking. Further studies are warranted to substantiate our findings.

Sulfur dioxide (SO2) is generally recognized as a respiratory irritant, but its effects if any at low levels of exposure are uncertain. We studied 38 power station technicians exposed to 0.8 ppm (parts per million) 8-h weighted levels of sulfur dioxide, and compared them to workers performing similar tasks without such exposure. Those exposed complained 5.8 times more frequently of cough (95% CI =1.8-20.6, P < 0.001), and also had significantly more sputum production. There was also a trend for increasing prevalence of dyspnea. On the other hand there was no decrease in pulmonary function test values. In the eight exposed subjects who complained of dyspnea, there was a significant decrease in pulmonary flow values. We conclude that power station workers exposed to low levels of SO2 have increased respiratory symptoms, and deserve compensation if their symptoms become chronic. The pulmonary function tests were not different from the control subjects, but there may be a small group who are prone to long-term morbidity. Additional studies are warranted to confirm our findings, and to define immediate and long-term morbidity due to low exposure to SO2.

The purpose of this study was to clarify the possible associations between the serum 1,25-dihydroxyvitamin D (calcitriol) level and blood pressure. Cross-sectional analysis of data was performed. Data collected included levels of serum calcitriol, parathyroid hormone, serum calcium, and blood lead; blood pressure; dietary history; and demographic and anthropometric variables. One hundred normotensive male industrial employees made up the study population. Systolic blood pressure and diastolic blood pressure were main outcome measures. After possible confounders were controlled for, multivariate analyses yielded an inverse, independent, and statistically significant association between calcitriol level and systolic blood pressure (standardized beta= -0.2704, P=.0051). A similar trend of borderline significance was found for the association between calcitriol and diastolic blood pressure (standardized beta= -0.1814, P=.0611). Parathyroid hormone, serum calcium, and blood lead levels were not associated with blood pressure. When subjects were divided into four groups by calcitriol level, those in the lowest quartile showed significantly higher systolic and diastolic blood pressures than those in the upper quartile (difference=11 mmHg, P=.007, and difference=4 mmHg, P=.071, respectively). There is an inverse association between serum calcitriol level and blood pressure. This suggests that in addition to its role in calcium homeostasis, the active metabolite of vitamin D may play a role in determining blood pressure. The differences in both systolic and diastolic blood pressures between the upper and lower quartiles of serum calcitriol were substantial and may be of clinical significance.

BACKGROUND: Blood pressure (casual and daytime) is higher in winter than it is in summer, and this factor might be partly responsible for the higher cardiovascular mortality in winter. OBJECTIVE: To determine in a prospective study whether there is also a seasonal variation in exercise blood pressure. METHODS: We evaluated the pretest, exercise (five-step treadmill test) and recovery values of systolic blood pressure (SBP), diastolic blood pressure (DBP), and heart rate of 94 healthy men, aged 20-65 years, during the summer and winter. RESULTS: SBP and DBP values were higher in winter than they were in summer during the resting period immediately before exercise (P = 0.003 and P = 0.07, respectively), and during recovery (both P < 0.0001). Exercise SBP and heart rate values were similar in the two seasons, although exercise DBP was higher in winter than it was in summer (P < 0.0001). The increase in DBP from pretest to stage 3 was 6.5 mmHg in summer and 10.4 mmHg in winter (P = 0.002). After we had controlled for possible confounders, the increase in DBP during exercise was found to be independently associated with season of the year and resting DBP. CONCLUSIONS: Exercise DBP varies according to season whereas exercise SBP does not. Our results suggest that, since measures of the response of blood pressure to exercise testing are frequently used in blood pressure and hypertension research as well as in clinical practice, the seasonal influences should be taken into account.

In general, blood pressure is higher in winter than in summer, and this factor may be partly responsible for the higher mortality from cardiovascular disease in winter. Cigarette smoking causes an acute pressor response that may interact with this cardiovascular response to cold exposure. We sought to determine whether the seasonal variation in blood pressure and heart rate differs between cigarette smokers and nonsmokers. We evaluated 24-hour ambulatory systolic blood pressure (SBP), ambulatory diastolic blood pressure (DBP), and ambulatory heart rate of 97 healthy men (73 nonsmokers and 24 smokers), 28 to 63 years of age, during the summer and winter, taking indoor temperatures into consideration. Smokers and nonsmokers both had higher daytime ambulatory SBPs and DBPs in winter than in summer (after adjustment for potential confounders). However, the winter increase seen in the smokers was significantly higher for mean daytime SBP (7.3 versus 2.7 mm Hg, P<.01), for mean daytime DBP (4.4 versus 3.1 mm Hg, P=.051), and for ambulatory heart rate (3.9 versus -1.7 beats/min, P<.001). The double product increased from summer to winter (daytime) by 10.53 for smokers and by only 0.11 for nonsmokers (P<.01). There was an independent interaction between season and smoking status that affected SBP (standardized beta=0.66, P<.0001) and DBP (standardized beta=0.32, P<.0001). Smokers have a greater seasonal variation in blood pressure and heart rate than nonsmokers and show a larger increase in the cardiovascular load in winter. Smoking apparently potentiates the cardiovascular response to various climatic conditions. Season should be taken into account in studies of blood pressure and in the diagnosis and treatment of hypertension, particularly among cigarette smokers.