Breast cancer risk and residence near industry or traffic in Nassau and Suffolk Counties, Long Island, New York.

A case-control interview study was used to evaluate the relationship between breast cancer risk and residential proximity to industrial facilities and traffic for pre- and postmenopausal women in Nassau and Suffolk Counties on Long Island, New York. A geographic information system was used to assign industry and traffic counts to 1-km2 grid cells (5-kM2 grid cells for traffic) and to assign potential exposure values to study subjects, based on 20-y residential histories. A significantly elevated risk of breast cancer was observed among postmenopausal subjects who were ever potentially exposed to chemical facilities (Nassau County adjusted odds ratio [OR] = 1.61, 95% confidence interval [95% CI] = 1.06-2.43; Suffolk County adjusted OR = 1.58, 95% CI = 0.71-3.51. This elevated risk, however, was not observed among premenopausal subjects. Risk increased for post-menopausal subjects as number of chemical facilities increased from one (adjusted OR = 1.45, 95% CI = 0.93-2.25) to two or more (adjusted OR = 3.47, 95% CI = 1.06-11.38). Crude and adjusted ORs for high traffic density were elevated among Nassau--but not Suffolk--county subjects and were not significant statistically.

Risk factors for developing eosinophilia myalgia syndrome among L-tryptophan users in New York.

Using a case-control study design, patients with eosinophilia myalgia syndrome (EMS) who had used L-tryptophan (LT) were compared with LT users who did not develop EMS. Of the 113 case patients and 95 controls who had used a retail brand that could be traced to a bulk LT producer, all (100%) case-patients and 69 (73%) controls used LT brands that were traced to Showa Denko K.K. (lower 95% CL = 10.0). Among the users of LT produced by Showa Denko K.K., the risk of EMS was greater for persons who used LT produced after December 1, 1988 (OR = 25.8, [95% CL = 7.1, 101.4]). The risk of developing EMS increased with increased dosage of LT, increased age, and use of LT as a sleeping aid. These epidemiologic data support the hypothesis that the etiologic agent in EMS is a contaminant introduced into LT products during production.

Occupational mercury exposure and male reproductive health.

This retrospective cohort study was designed to investigate the relationship of male occupational exposure to elemental mercury and several reproductive outcomes. All subjects worked at least 4 months between 1953 and 1966 at a plant that used elemental mercury; 247 white male employees who had the highest exposures were compared to 255 matched nonexposed employees. Individual exposure to mercury was estimated from urinary mercury measurement records. Information on reproductive history and potential confounding variables was obtained through personal interview with each of the employees and with a subset of their wives. No associations were demonstrated between mercury exposure and decreased fertility or increased rates of major malformations or serious childhood illnesses. After controlling for previous miscarriage history, mercury exposure was not a significant risk factor for miscarriage. Because of this study's potential problems with long-term recall, further studies of the effect of mercury on pregnancy outcome are warranted in other populations.

Neurological abnormalities associated with remote occupational elemental mercury exposure.

We examined 502 subjects, 247 of whom had occupational elemental mercury exposures 20 to 35 years previously, to identify potential exposure-related neurological abnormalities. Few significant (p less than 0.05) differences existed between exposed and unexposed subjects. However, multiple linear regression analysis demonstrated several significant correlations between declining neurological function and increasing exposure as determined by urine mercury measurements from the exposure interval. Subjects with urine mercury peak levels above 0.6 mg/L demonstrated significantly decreased strength, decreased coordination, increased tremor, decreased sensation, and increased prevalence of Babinski and snout reflexes when compared with the remaining subjects. Furthermore, subjects with clinical polyneuropathy had significantly higher peak levels than normal subjects (0.85 vs 0.61 mg/L; p = 0.04), but not increased exposure duration (20.1 vs 20.8 quarters; p = 0.34), and 28% of subjects with peak levels above 0.85 mg/L had clinical evidence of polyneuropathy, compared with 10% of remaining subjects (p = 0.005). Although exposure was not age dependent, several neurological measures showed significant age-mercury interaction, suggesting that natural neuronal attrition may unmask prior exposure-related subclinical abnormalities.