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    A. Ruder

    Production of polychlorinated biphenyls (PCBs) ended in the United States in the 1970s, but PCBs persist in the environment and are detectable in the blood of approximately 80% of Americans over age 50. PCBs decrease dopamine levels in... more
    Production of polychlorinated biphenyls (PCBs) ended in the United States in the 1970s, but PCBs persist in the environment and are detectable in the blood of approximately 80% of Americans over age 50. PCBs decrease dopamine levels in rats and monkeys. Loss of dopamine is the hallmark of Parkinson disease, a neurodegenerative disease. There are no epidemiologic studies of PCBs and neurodegenerative disease. We conducted a retrospective mortality study of 17,321 PCB-exposed workers to determine whether mortality from Parkinson disease, dementia, and amyotrophic lateral sclerosis was elevated compared with the U.S. population. All workers had a least 90 days employment in 1 of 3 electrical capacitor plants using PCBs from the 1940s to the 1970s. PCB serum levels from a sample of these workers in the 1970s were approximately 10 times the level of community controls. We found no overall excess of Parkinson disease, amyotrophic lateral sclerosis, or dementia in the PCB-exposed cohort (standardized mortality ratios [SMRs]-1.40, 1.11, and 1.26, respectively, and number of deaths-14, 10, and 28 respectively). However, sex-specific analyses revealed that women had an excess of amyotrophic lateral sclerosis (SMR-2.26; 95% confidence interval [CI] = 1.08-4.15; 10 deaths). Furthermore, among highly exposed women (defined by a job-exposure matrix), we found an excess of Parkinson disease (SMR-2.95; 95% CI = 1.08-6.42; 6 deaths) and dementia (SMR-2.04; 95% CI = 1.12-3.43; 14 deaths). Our data are limited due to small numbers and reliance on mortality rather than incidence data, but are suggestive of an effect of PCBs on neurodegenerative disease for women. The literature does not offer an explanation for why women would be more affected than men by PCB exposure for these outcomes.
    Epidemiologic evidence on the relationship between selected industries and cancer is reviewed. This article will focus on several industries which have not been covered elsewhere in this volume, briefly describe current research on cancer... more
    Epidemiologic evidence on the relationship between selected industries and cancer is reviewed. This article will focus on several industries which have not been covered elsewhere in this volume, briefly describe current research on cancer in the agricultural and construction industries, and discuss surveillance data on cancer mortality in relation to industry listed on US death certificates. Employment in the rubber industry has been associated with bladder cancer, leukemia, stomach, and lung cancer and is considered by the International Agency for Research on Cancer (IARC) to have 'sufficient evidence of carcinogenicity in humans.' Studies of workers exposed to polychlorinated biphenyls (PCBs) have reported excess mortality from gastrointestinal neoplasms, hematologic neoplasms, and skin cancer (specifically malignant melanoma); IARC considers that the evidence for carcinogenicity in humans is 'limited.' Employment in the boot and shoe industry has been associated w...
    Our epidemiological study investigated lateral epicondylitis (tennis elbow) among 150 nonprofessional male tennis players (75% of the players approached consecutively) interviewed and examined physically at four local tennis clubs. The... more
    Our epidemiological study investigated lateral epicondylitis (tennis elbow) among 150 nonprofessional male tennis players (75% of the players approached consecutively) interviewed and examined physically at four local tennis clubs. The interview and examination covered over sixty possible risk factors, including demographic data, playing habits, anatomical measurements and racket characteristics. The "average" painfree player is 38 years old, has played tennis 11 years, and plays 5.5 hours a week, usually with a racket whose head area is 570 cm2. The "average" tennis elbow sufferer is a 45-year-old player who has been playing 16 years and has played 8 hours weekly before onset of pain with a racket whose head area is 613 cm2. Multivariate analysis indicated that number of playing years has no independent effect beyond its association with age. Playing hours per week, current age and age at pain onset have independent significant effects on number of pain episodes...
    To further evaluate the association of styrene, fibreglass, and wood dust exposure with non-malignant diseases, we extended follow-up through 2008 for 5203 workers exposed to styrene, fibreglass, and wood dust between 1959 and 1978 at two... more
    To further evaluate the association of styrene, fibreglass, and wood dust exposure with non-malignant diseases, we extended follow-up through 2008 for 5203 workers exposed to styrene, fibreglass, and wood dust between 1959 and 1978 at two boat building plants. We used a person-years analysis program, LTAS.NET to compute standardised mortality ratios (SMRs) using Washington State and U.S. rates, standardised rate ratios (SRRs), and 95% confidence intervals. SMRs were stratified by exposure category (low or high) and duration of employment category (≤ 1 year, 1+ years). Overall, 1206 nonmalignant deaths occurred (WA SMR 1.14, CI 1.08-1.21), with excess mortality for chronic obstructive pulmonary disease (COPD) overall (n = 112, WA SMR 1.61, CI 1.32-1.93), and among 2063 workers highly exposed to styrene and fibreglass (n = 39, WA SMR 2.37, CI 1.69-3.25). Results were similar using U.S. mortality rates. Workers employed for less than one year had statistically significant increased mortality from several lifestyle-related outcomes (alcoholism, ischaemic heart disease, cirrhosis, accidental poisoning and homicide). The excess COPD mortality in this cohort is difficult to interpret. Recent reports associate styrene/fibreglass reinforced plastic manufacturing with another respiratory disease - bronchiolitis obliterans. Based on a review of COPD death certificates, bronchiolitis obliterans does not appear to be a contributing factor for excess COPD mortality. The COPD excess in this study points to a need for an in-depth investigation of respiratory disease and occupational styrene exposure. Short term worker results are consistent with other occupational cohort studies.
    Perchloroethylene (PERC) is used widely as an industrial dry cleaning solvent and metal degreaser. PERC is an animal carcinogen that produces increased incidence of renal adenomas, adenocarcinomas, mononuclear cell leukemia, and... more
    Perchloroethylene (PERC) is used widely as an industrial dry cleaning solvent and metal degreaser. PERC is an animal carcinogen that produces increased incidence of renal adenomas, adenocarcinomas, mononuclear cell leukemia, and hepatocellular tumors. Oxidative DNA damage and lipid peroxidation were assessed in 38 women with (dry cleaners) or without (launderers) occupational exposure to PERC. PERC exposure was assessed by collecting breathing zone samples on two consecutive days of a typical work week. PERC levels were measured in blood drawn on the morning of the second day of breathing zone sample collection in dry cleaners and before a typical workday in launderers. Blood PERC levels were two orders of magnitude higher in dry cleaners compared to launderers. A significant correlation was noted between time weighted average (TWA) PERC and blood PERC in dry cleaners (r=0.7355, P<0.002). 8-Hydroxydeoxyguanosine (8-OHdG), ng/mg deoxyguanosine (dG) in leukocyte nuclear DNA was used as an index of steady-state oxidative DNA damage. Urinary 8-OHdG, microg/g creatinine was used as an index of oxidative DNA damage repair. Urinary 8-epi-prostaglandin F(2alpha) (8-epi-PGF), ng/g creatinine was used as an index of lipid peroxidation. The mean+/-S.D. leukocyte 8-OHdG in launderers was 16.0+/-7.3 and was significantly greater than the 8.1+/-3.6 value for dry cleaners. Urinary 8-OHdG and 8-epi-PGF were not significantly different between dry cleaners and launderers. Unadjusted Pearson correlation analysis of log transformed PERC exposure indices and biomarkers of oxidative stress indicated a significant association in launderers between blood PERC and day 1 urinary 8-OHdG (r=0.4661, P<0.044). No significant associations between exposure indices and biomarkers were evident in linear models adjusted for age, body mass index, race, smoking (urinary cotinine, mg/g creatinine) and blood levels of the antioxidants Vitamin E and beta-carotene. The mean+/-S.D. leukocyte 8-OHdG value in control white women was 17.8+/-7.4 and was significantly greater than the 11.8+/-5.9 in control black women. No significant differences by race were evident for the other biomarkers. Smoking status was not significantly associated with any of the oxidative damage indices. Results indicate a reduction in oxidative DNA damage in PERC exposed dry cleaners relative to launderers, but PERC could not clearly be defined as the source of the effect.
    Mortality was updaated through 2008 for 5203 workers exposed to styrene, fibreglass, and wood dust between 1959 and 1978 at two boatbuilding plants. The a priori hypothesis: leukaemia and lymphoma excesses would be found Standardised... more
    Mortality was updaated through 2008 for 5203 workers exposed to styrene, fibreglass, and wood dust between 1959 and 1978 at two boatbuilding plants. The a priori hypothesis: leukaemia and lymphoma excesses would be found Standardised mortality ratios (SMR), standardised rate ratios (SRR), and 95% confidence intervals (CI) were calculated using Washington State rates and a person-years analysis program, LTAS. NET, controlling for age, calendar period, race, and gender. The SRR analysis compared tertiles of estimated cumulative styrene exposure. Overall, 484 cancer deaths occurred (SMR 1.20, CI 1.10-1.31), with excess mortality for respiratory cancers (n = 171, SMR 1.33, CI 1.14-1.55) and prostate cancer (n = 41, SMR 1.44, CI 1.03-1.96). Among 2063 workers highly exposed to styrene and fibreglass there were excesses of mesothelioma (n = 3, SMR 5.28, CI 1.09-15.4) and ovarian cancer (n = 6, SMR 2.94, CI 1.08-6.41). The SRR analysis did not find strong associations between tertiles of styrene exposure and cancer mortality. We found no excess leukaemia or lymphoma mortality. Unanticipated excess mesothelioma and ovarian cancer mortality are difficult to interpret and could be due to fibreglass exposure or employment elsewhere, or could be chance findings.