Paracrine stimulation of cell growth by cholecystokinin/gastrin through cholecystokinin-B receptor on GH3 cells in vitro

Self-reported reproductive histories of male employees of a lead-zinc smelter were related to pre-conception measures of lead exposure to examine associations between paternal occupational lead exposure and adverse pregnancy outcome. The participants reported 2,021 pregnancies which resulted in 1,684 normal live births, 12 stillbirths, 30 birth defects, 203 spontaneous abortions, and 92 "other" outcomes. Birth defects and stillbirths were combined for the analysis. The risk of a stillbirth or birth defect was elevated for pre-conception employment in a high-lead-exposure compared with a low-lead-exposure job (odds ratio = 2.7, 95% confidence interval = 0.7, 9.6). A similar risk was found for pre-conception blood lead levels of 25-39 μg/dL and >/= 40 μg/dL when compared with blood lead levels of < 25 μg/dL (OR = 2.9, 95% CI = 0.6, 13.3, and OR = 2.5, 95% CI = 0.5, 11.6, respectively). No association was found between pre-conception lead exposure and spontaneous abortion. A relatively low response rate to the questionnaire and potentially erroneous reporting of reproductive outcomes by male workers are limitations of the study.     

Occupational Exposures and Risks of Spontaneous Abortion among Female Veterinarians

Associations between occupational exposures and spontaneous abortion (SA) in a cohort of female veterinarians were studied with pregnancy and job-exposure history data collected as part of a mixed-mode survey of all women graduating from U.S. veterinary colleges during the 11-year period 1970-1980 (N = 2,997; response rate 85.0%). Data analysis focused on SA risks among postgraduation pregnancies in relation to 1) type of clinical practice at the time of conception and 2) self-reported occupational exposures to 13 exposure entities. Multiple logistic regression was used to control for the potentially confounding effects of maternal age, gravidity, previous SA, and smoking and drinking behaviors. Pregnancies reported by veterinarians employed in all-equine practices were at highest relative risk of spontaneous abortion when compared with pregnancies reported by unemployed veterinarians [confounder-adjusted odds ratio (aOR) = 2.1; 95% confidence interval (CI), 0.6-7.4]. Agent-specific relative risk estimates ranged from 0.7 to 1.1, suggesting little or no excess risk. However, when analyses were restricted to small-animal practitioners, there was a weak association between SA risk and job-related exposure to ionizing radiation (aOR equals; 1.3; 95% CI, 0.8-2.0), a finding not inconsistent with the results of two other studies of female veterinarians. Although this study showed no strong associations, the results suggest a relationship between SA among female veterinarians and certain exposure types, and thus focus attention on other workers who encounter similar on-the-job hazards.     

The N-terminus of Nef from HIV-1/SIV associates with a protein complex containing Lck and a serine kinase

A multi-center case-referent study was conducted on the relation between paternal occupational exposure and spina bifida in offspring. Cases were born between 1980 and 1992 in The Netherlands. Referents were recruited from hospitals and from the general population. Postal questionnaires were used to gather information on occupation and potential confounders. Through job-specific telephone interviews with 122 case fathers and 411 referent fathers, detailed exposure information was collected on specific tasks, the use of chemical or physical agents, frequency of exposure, and use of protective equipment. The study yielded statistically significant associations between spina bifida and low exposure to welding fumes (OR = 1.6, 95% CI: 1.0-2.6) and low exposure to UV radiation during welding (OR = 2.6, 95% CI: 1.2-5.6), and suggestive findings of an association between spina bifida and moderate or high exposure to cleaning agents, moderate or high pesticide exposure (OR = 1.7, 95% CI: 0.7-4.0), and stainless steel dust (OR = 2.0, 95% CI: 0.8-5.2). No associations were identified for other paternal occupational exposures, such as organic solvents.     

Laboratory work and pregnancy outcome

Spontaneous abortions among women working in laboratories, and congenital malformations and birth weights of the children were examined in a retrospective case-referent study. In the spontaneous abortion study there were 535 women (206 cases and 329 referents), and in the malformation study 141 women (36 cases and 105 referents). The analysis of the birth weights concerned 500 women (referents). Significant associations with spontaneous abortion were found for exposure to toluene (odds ratio [OR], 4.7, 95% confidence interval [CI], 1.4 to 15.9), xylene (OR 3.1, CI 1.3 to 7.5) and formalin (OR 3.5, CI 1.1 to 11.2) > or = 3 days a week, adjusted for the covariates. Most of the women exposed to formalin and xylene were working in pathology or histology laboratories. No association with congenital malformation was found.     

The risk of Parkinson's disease with exposure to pesticides, farming, well water, and rural living

We assessed exposure to pesticides, farming, well water use, and rural living as risk factors for Parkinson's disease (PD) in a population-based case-control study consisting of men and women > or = 50 years of age who had primary medical care at Henry Ford Health System in metropolitan Detroit. Enrolled PD patients (n = 144) and control subjects (n = 464) were frequency-matched for age, race, and sex. When adjusted for these variables and smoking status, there was a significant association of occupational exposure to herbicides (odds ratio [OR], 4.10; 95% CI, 1.37, 12.24) and insecticides (OR, 3.55; 95% CI, 1.75, 7.18) with PD, but no relation was found with fungicide exposure. Farming as an occupation was significantly associated with PD (OR, 2.79; 95% CI, 1.03, 7.55), but there was no increased risk of the disease with rural or farm residence or well water use. The association of occupational exposure to herbicides or insecticides with PD remained after adjustment for farming. The association of farming with PD was maintained after adjustment for occupational herbicide exposure and was of borderline significance after adjustment for occupational insecticide exposure. These results suggest that PD is associated with occupational exposure to herbicides and insecticides and to farming and that the risk of farming cannot be accounted for by pesticide exposure alone.     

Reducing pregnancy and induced abortion rates in China: family planning with husband participation

OBJECTIVES: This study assessed the effectiveness of a family planning intervention with and without husband's participation in reducing pregnancy and abortion rates in Shanghai, China. METHODS: In this 3-arm randomized trial among 1800 nonsterilized married women, educational interventions targeting both spouses and targeting the wife only were compared with usual family planning care. RESULTS: Among women not using intrauterine devices (IUDs), the intervention with husband's participation had an effect in reducing pregnancy rates (adjusted odds ratio [OR] = 0.36, 95% confidence interval [CI] = 0.12, 1.1) and abortion rates (adjusted OR = 0.29, CI = 0.09, 0.94) compared with control subjects, and a significant effect in reducing pregnancy rates (adjusted OR = 0.29, CI = 0.10, 0.85) and abortion rates (adjusted OR = 0.24, CI = 0.07, 0.77) compared with wife-only subjects. CONCLUSIONS: Family planning interventions involving husbands may reduce pregnancy and abortion rates among non-IUD users.     

Coffee consumption and risk of hospitalized miscarriage before 12 weeks of gestation

In order to analyse the association between drinking coffee in pregnancy and risk of spontaneous abortion, a case-controlled study was conducted in Milan, Northern Italy. Cases were 782 women with spontaneous abortion within the 12th week of gestation. The control group was recruited from women who gave birth at term (> 37 weeks gestation) to healthy infants on randomly selected days at the same hospitals where cases had been identified: 1543 controls were interviewed. A total of 561 (72%) cases of spontaneous abortion and 877 (57%) controls reported coffee drinking during the first trimester of the index pregnancy. The corresponding multivariate odds ratios of spontaneous abortion, in comparison with non-drinkers, were 1.2, 1.8 and 4.0, respectively, for drinkers of 1, 2 or 3, and 4 or more cups of coffee per day. No relationship emerged between maternal decaffeinated coffee, tea and cola drinking in pregnancy, as well as paternal coffee consumption, and risk of spontaneous abortion. With regard to duration in years of coffee drinking, the estimated multivariate odds ratios of spontaneous abortion were, in comparison with non-coffee drinkers, 1.1 (95% confidence interval (CI) 0.9-1.4) and 1.9 (95% CI 1.5-2.6) for women reporting a duration of coffee consumption < or = 10 or > 10 years. In conclusion, coffee drinking early in pregnancy was associated with an increased risk of abortion. This has biological implications, but epidemiological inference on the causality is difficult and still open to debate.     

The role of neuropaediatrician in the comprehensive management of children with cerebral palsy]

Nonmalignant respiratory disease (NMRD) mortality was examined among woodworkers participating in the American Cancer Society's CPS-II cohort study. During the 6-year prospective follow-up there were 97 NMRD death's among 11,541 men reporting employment in wood-related occupations and 1,338 NMRD deaths among 317,424 men reporting no exposure to wood dust or wood-related jobs. Relative risks, adjusted for age and smoking, were calculated using Poisson regression. A small excess of NMRD was observed among woodworkers. However, the relative risk was higher among woodworkers who did not report exposure to wood dust (RR = 1.52, 95% CI = 1.18-1.97) than those who did (RR = 1.27, 95% CI = 0.91-1.77), and no clear trend with duration of exposure was observed. An excess of NMRD was observed among woodworkers reporting exposure to asbestos (RR = 1.59, 95% CI = 0.85-2.96), as well as the small number of woodworkers reporting exposure to formaldehyde (RR = 1.95, 95% CI = 0.63-6.06), but men not reporting exposure to these substances also had an excess risk. Although limited by a short follow-up period and crude indicators of exposure, the strengths of this analysis were the ability to compare woodworkers to a similar, healthy population and to adjust for the effects of smoking. Cohort studies with better exposure information are needed to examine the role of occupational exposures among woodworkers in the etiology of respiratory disease.     

Caffeinated beverages, decaffeinated coffee, and spontaneous abortion

We examined the relations between spontaneous abortion and the consumption of caffeine, individual caffeine-containing beverages (coffee, tea, and soda), and decaffeinated coffee in a prospective study of 5,144 pregnant women. We collected information about potential risk factors for spontaneous abortion, including consumption of caffeinated beverages and decaffeinated coffee before and during pregnancy, by interview in the first trimester. Neither total estimated caffeine nor individual caffeinated beverage consumption during the first trimester was associated with an appreciable increase in risk for spontaneous abortion. The adjusted odds ratio for consumption of greater than 300 mg per day of caffeine was 1.3 [95% confidence interval (CI) = 0.8-2.1] after adjustment for maternal age, pregnancy history, cigarette and alcohol consumption, employment, race, gestational age at interview, and marital and socioeconomic status. The adjusted odds ratio for spontaneous abortion related to consumption of three or more cups of decaffeinated coffee during the first trimester was 2.4 (95% CI = 1.3-4.7) in the same model. Although we could not demonstrate this with available data, we suspect that this association was due to bias resulting from the relations among fetal viability, symptoms of pregnancy such as nausea, and consumption patterns during pregnancy.     

Design, construction, implementation, and cost of a hospital pharmacy cleanroom

The authors sought to clarify in a cross-sectional study the possible associations between homeostatic regulators of calcium and occupational exposure to lead. Subjects were 146 industrial male employees, 56 with and 90 without occupational lead exposure. The main outcome measures were serum concentration of parathyroid hormone (PTH) and 1,25-dihydroxyvitamin D (calcitriol). The median values of blood lead were 40.5 microg/dl in the exposed group and 4.0 microg/dl in the controls. There were no differences between groups in dietary history and serum calcium levels. PTH and calcitriol levels were significantly higher in the exposed than in the nonexposed subjects (42.0+/-24.2 vs. 33.6+/-14.9 pg/ml, p <0.05; and 83.8+/-27.0 vs. 67.9+/-17.6 pmol/liter, p <0.001, respectively). Multivariate analyses showed that after controlling for possible confounders, occupational lead exposure (no/yes) was independently associated with PTH level (pg/ml) (beta = 7.81, 95% confidence interval (CI) 3.7-11.5) and with calcitriol (pmol/liter) (beta = 12.3, 95% CI 3.84-20.8). It is concluded that subjects occupationally exposed to lead show a substantial compensatory increase in PTH and calcitriol activities which keep serum calcium levels within normal range. This may be of clinical significance since a sustained increase in calcitropic hormones in susceptible subjects may eventually increase the risk of bone disorders.     

Relationship between abortions and seroprevalences to selected infectious agents in dairy cows

The aim of this study was to determine whether the occurrence of abortion is related to the seroprevalence of abortion-causing infectious agents. In a cross-sectional study, cattle from dairy farms in Switzerland that were defined as having an abortion problem were divided into two groups: cows with a history of abortion within the previous 3 months (cases) and cows without a history of abortion (controls). A positive titre to Leptospira spp. was associated with an increased probability of being a case (OR = 1.74, 95% CI = 1.21-2.47). There were interactions between Coxiella burnetti titre and parity, and between Chlamydia psittaci and C. burnetti titre and breed. Multiparous cases after the second lactation with a positive titre to C. burnetti were less likely (OR = 0.42, 95% CI = 0.22-0.82) to be cases. Swiss Browns (Swiss Braunvieh and Brown Swiss) with a positive titre to C. psittaci and Swiss Browns with a positive titre to C. burnetti were more likely (OR = 1.63, 95% CI = 1.13-2.37 and OR = 1.79, 95% CI = 1.15-2.78, respectively) to be cases. Parity alone was not associated with the occurrence of abortion.     

Mortality and incidence of cancer among sewage workers: a retrospective cohort study

To study the incidence of and mortality from cancer among sewage workers a retrospective analysis was performed on a cohort of 656 men employed for at least one year at any one of 17 Swedish sewage plants during the years 1965-86. Assessment of exposure was done by classification of work tasks. Lower than expected total mortality (standardised mortality ratio (SMR) = 0.75, 95% confidence interval (95% CI) 0.58-0.97) and cardiovascular mortality (SMR = 0.61, 95% CI 0.39-0.91) was found. This was interpreted as a result of the healthy worker effect. For all cancers combined the mortality (SMR = 1.08, 95% CI 0.68-1.67) and morbidity (SMR = 1.02, 95% CI 0.72-1.38) were comparable with those of the general population. There were increased incidences for brain tumours (SMR = 2.19, 95% CI 0.45-6.39), gastric cancers (SMR = 2.73, 95% CI, 1.00-5.94), and renal cancers (SMR = 1.68, 95% CI = 0.35-4.90). For lung cancer the risk was reduced (SMR = 0.70, 95% CI 0.15-2.05). Allowance for a latency period of 10 years from the start of exposure did not change the pattern. Logistic modelling was used to search for exposure-response relations. In a logistic model with the confounder age forced in, renal cancer had a significant positive relation with a weighted sum of employment times, where the weights describe the classification of exposure. No exposure-response relations were found for brain tumors or gastric cancers. The increased risks are based on small numbers of cases. A future follow up will add more conclusive power to the study. Specific exposures need to be identified to allow for a better dose-response analysis.     

Optimization of energy-dependent processes in mitochondria from rat liver and brain after inhalation of negative air ions

BACKGROUND: Bone cancers in children are serious and highly fatal conditions, yet relatively little is known about their causes or methods of prevention. METHODS: The relationship between parental occupation and bone cancer in offspring was explored in a case-control study. Cases were identified from the Ontario Cancer Registry; population-based controls were matched on sex and age. Data were collected from their parents through the use of a mailed self-administered questionnaire. RESULTS: The odds ratio estimates (OR) for bone cancer were elevated for fathers in the social sciences (OR = 2.5, 95% confidence interval [CI]: 0.7-8.4). Risk of Ewing's sarcoma was significantly high among children with fathers in social sciences (OR = 6.2, 95% CI: 1.6-24.5) and mothers in teaching (OR = 3.1, 95% CI: 1.1-8.7) or farming (OR = 7.8, 95% CI: 1.9-31.7). Osteosarcoma risk was increased for fathers in farming (OR = 2.1, 95% CI: 0.8-5.7), and mothers in managerial and administrative work (OR = 2.3, 95% CI: 0.6-8.1), and product fabricating, assembling, and repairing (OR = 2.0, 95% CI: 0.6-7.2). CONCLUSIONS: Certain methodological problems plague studies of bone cancer in children (e.g. small studies, low statistical power, analysis of multiple occupational categories, difficulty in identifying specific carcinogenic agents). These associations require further investigation, especially as elevated risks have been reported previously for agricultural occupations.     

Immunological markers among workers exposed to 2,3,7,8-tetrachlorodibenzo-p-dioxin

OBJECTIVES: To examine the association of immune cell number and function with occupational exposure to substances contaminated with 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD). METHODS: A cross sectional medical survey. The exposed participants were employed at two chemical plants between 1951 and 1972 in the manufacture of 2,4,5-trichlorophenate and its derivatives. The reference group consisted of people with no occupational exposure to phenoxy herbicides who lived within the communities of the workers. Data from a total of 259 workers and 243 unexposed referents were included in the analysis of immune function. Laboratory tests for immune status included enumeration of circulating leukocyte and lymphocyte populations, proliferative responses of circulating lymphocytes to mitogens and antigens, and serum concentrations of the major immunoglobulins and complement factor C3. RESULTS: The workers had substantial exposure to substances contaminated with TCDD, as indicated by a lipid adjusted mean serum TCDD concentration of 229 ppt compared with a mean of 6 ppt in the unexposed referents. Workers were divided into categories based on their serum TCDD concentration. For all categories except the lowest, with values of serum TCDD comparable with the unexposed referents, there were increased odds of having lower counts of CD26 cells (activated T cells) (odds ratio (OR) 1.0, 95% confidence interval (95% CI) 0.5 to 1.8 for TCDD < 20 ppt; OR 1.6, 95% CI 0.8 to 3.2 for TCDD 20-51 ppt; OR 2.7, 95% CI 1.4 to 5.1 for TCDD 52-125 ppt; OR 2.6, 95% CI 1.4 to 4.9 for TCDD 125-297 ppt; OR 2.4, 95% CI 1.3 to 4.6 for TCDD 298-3389 ppt). A less consistent finding was decreased spontaneous proliferation of cultured lymphocytes. However, increases were found in proliferation of lymphocytes in response to concanavalin and pokeweed in workers in the high TCDD category. Age, cigarette smoking, and alcohol were significant predictors of several immunological outcomes. CONCLUSIONS: Associations between serum TCDD concentration and both a decrease in circulating CD26 cells and decreased spontaneous background proliferation were the major findings of this study. These results are unlikely to be of clinical importance but may reflect limited evidence for an association between immunological changes in workers and high serum concentrations of TCDD, or chance findings resulting from the evaluation of multiple immunological variables.     

Humeral epicondylitis among gas- and waterworks employees

OBJECTIVES: In this cross-sectional study 290 male employees of the public gas- and waterworks of Hamburg, Germany, were examined for symptoms of epicondylitis. Forty-one workers were diagnosed with symptoms of lateral or medial epicondylitis. The effect of employment in different job categories on the prevalence of epicondylitis was explored. METHODS: The diagnosis of epicondylitis was based on the study's own criteria and compared with criteria used in former studies. Jobs were categorized into high, moderate, and no exposure groups according to tasks regarded as strenuous for the elbow. The data were analyzed with the help of multivariate logistic regression. RESULTS: With the study's diagnostic criteria, the prevalence odds ratio (OR) for 10 years of high exposure to elbow straining work was 1.7 [95% confidence interval (95% CI) 1.04-2.68] for currently held jobs and 2.16 (95% CI 1.08-4.32) for formerly held jobs. For workers regarded as moderately exposed in current jobs the odds ratio for 10 years was 1.4 (95% CI 1.00-1.93). Very similar results were obtained for current exposure when stricter diagnostic criteria were employed. CONCLUSIONS: The results suggest a cumulative exposure effect with length of employment. Workers with high exposure in former jobs compared with employees with high exposure in their current job exhibited more residual or slight epicondylitis symptoms upon examination.     

Nontyrosine crystalloids in fine-needle aspiration specimens of the parotid gland: a report of two cases and review of the literature

Transitional-cell carcinoma is the dominant histological type of malignant tumors of the urinary bladder. There is limited information on risk factors for non-transitional-cell carcinoma (NTCC) of the bladder. We used data from 9 case-control studies on bladder cancer from 6 European countries to examine the association between NTCC, tobacco smoking and occupation. Information on 146 cases diagnosed with NTCC were matched by age, gender and study center to 727 non-cancer population or hospital controls and also with 722 transitional-cell-bladder-cancer controls. Lifetime smoking and occupational history were evaluated. A statistically significant excess risk for NTCC was observed for current smoking [odds ratio (OR) = 3.61, 95% confidence interval (CI) 2.08-6.28]. The risk increased with higher tobacco consumption (OR for highest tertile of pack-years = 7.01, 95% CI 3.60-13.66). The risks were higher for squamous-cell carcinomas than for other types of NTCC. Among major occupational groups, a significant excess risk was seen for field-crop and vegetable-farm workers (OR = 2.06, 95% CI 1.03-4.10). These results indicate that NTCC of the bladder is associated with smoking and specific occupations. The risk pattern seems to differ, in part, from that observed for transitional-cell carcinoma of the bladder.     

Case-control study of occupational exposures and male breast cancer

OBJECTIVE: To investigate whether risk of male breast cancer is associated with workplace exposures. METHODS: A case-control study of 178 cases of male breast cancer and 1041 controls was carried out with data from the United States national mortality follow-back survey, which collected questionnaire information from proxy respondents of a 1% sample of all 1986 United States deaths among subjects aged 25-74 years. Occupational exposure to electromagnetic fields, high temperatures, polycyclic aromatic hydrocarbons (PAHs), herbicides, other pesticides, and organic solvents was assessed by applying job-exposure matrices, based on the 1980 United States census occupation and industry codes, to the longest job held by study subjects as reported by the informants. A socioeconomic status index was created by combining information on annual family income, education, assets, and occupation to assess the association of socioeconomic status with male breast cancer. Relative risks were derived from logistic regression modelling, which included age, socioeconomic status, marital status, and body mass index, as well as occupational exposures. RESULTS: Risk for male breast cancer increased significantly with increasing socioeconomic status index (test for trend: p < 0.01), but the risks associated with individual socioeconomic status variables were smaller and the trends were not significant. A significant increase in risk of male breast cancer was associated with employment in blast furnaces, steel works, and rolling mills (odds ratio (OR) 3.4; 95% confidence interval (95% CI) 1.1 to 10.1, based on six cases), and motor vehicle manufacturing (OR 3.1; 95% CI 1.2 to 8.2, based on seven cases). However, exposures to electromagnetic fields, high temperature, PAHs, herbicides, other pesticides, and organic solvents were not associated with risk of male breast cancer. CONCLUSIONS: The role of workplace exposures in increasing risk of breast cancer among men employed in motor vehicle manufacturing and in blast furnaces, steel works, and rolling mills deserves further investigation. The finding on socioeconomic status suggests that, as well as reproductive factors, other lifestyle factors such as diet that may be related to high socioeconomic status in men should be investigated further.     

Pesticide exposures and fetal death: a review of the epidemiologic literature

Despite considerable concern regarding the effects on reproductive outcome of exposures to pesticides, convincing evidence for the developmental toxicity of occupational and environmental pesticide exposure in humans is lacking. In this comprehensive review of the English language epidemiologic literature, we summarize studies that have examined potential associations between fetal deaths (both spontaneous abortions and stillbirths) and specific pesticides, as well as maternal and paternal employment in occupations with potential for exposure. While many of the epidemiologic studies to date suffer from methodologic problems, the data are suggestive of increased risks of fetal deaths associated with pesticides in general and maternal employment in the agricultural industry. There is a clear need for epidemiologic research that focuses on specific pesticide products or chemical families, with improved exposure assessment. The potential role of solvents in developmental toxicity associated with pesticide use by both males and females should also be considered.     

Physical work load and pregnancy outcome

Pronounced physical exertion may influence intraabdominal pressure and uterine blood flow, hormonal balance, and nutritional status, all of which are important determinants of embryonic and fetal development and survival. Most of the epidemiologic evidence of reproductive effects from occupational physical activity concerns gestational age/premature birth, birth weight/intrauterine growth retardation, and spontaneous abortion. Strenuous work, especially when involving long hours of standing and walking, seems to increase the risk of preterm delivery. The effect on intrauterine growth and spontaneous abortion risk is less clear. As a single factor, heavy lifting has in most circumstances not been associated with a significantly increased risk of these outcomes. In general, heavy work duties should be avoided, and enough rest periods assured, especially in late pregnancy.     

Non-physician providers may ease oncology work force crisis

OBJECTIVE: To evaluate the risk of hepatitis A virus (HAV) infection among sewage workers from occupational exposure to raw sewage. METHODS: An analytical cross sectional study of 241 company employees with possible occupational exposure to sewage in a large water and sewerage company was carried out. Previous exposure to hepatitis A virus infection was assessed, as were its associations with possible risk factors. RESULTS: Frequent occupational exposure to raw sewage was a significant risk factor for HAV infection, independently of other known risk factors (odds ratio 3.73, 95% confidence interval 1.48 to 9.37). Of 50 employees who reported occupational exposure to raw sewage most of the time, 30 (60%) had had HAV infection. CONCLUSION: Employees who are likely to be at risk of frequent exposure should have their immunity ensured. The salivary assay for IgG anti-HAV used in the study was highly specific and would be suitable for prevaccination testing of older employees, who are more likely to be immune.