We conducted a study among residents of a small community contaminated with heavy metals from a defunct zinc smelter and residents from a comparison community to determine whether biologic measures of cadmium exposure were associated with biomarkers of early kidney damage. Creatinine-adjusted urinary cadmium levels did not differ between the smelter and comparison communities; thus we combined individuals from both communities (n = 361) for further analyses. The overall mean urinary cadmium level was low, 0.26 microg/g creatinine, similar to reference values observed in the U.S. general population. For children ages 6-17 years, urinary concentration of N-acetyl-beta-D-glucosaminidase (NAG), alanine aminopeptidase (AAP), and albumin were positively associated with urinary cadmium, but these associations did not remain statistically significant after adjusting for urinary creatinine and other potential confounders. For adults ages 18 or older, urinary concentration of NAG, AAP, and albumin were positively associated with urinary cadmium. The associations with NAG and AAP but not with albumin remained statistically significant after adjusting for creatinine and other potential confounders. We found a positive dose-effect relationship between levels of creatinine-adjusted urinary cadmium and NAG and AAP activity, and statistically significant differences in mean activity for these two enzymes between the highest (> or =1.0 microg cadmium/g creatinine) and the lowest (< or =0.25 microg cadmium/g creatinine) exposure groups. The findings of this study indicate that biologic measures of cadmium exposure at levels below 2.0 microg/g creatinine may produce measurable changes in kidney biomarkers.

dysfunction among styreneexposed workers. Scand J Work Environ Health 1995;21:382-90. Objectives The present study was undertaken to examine the relation between visual functions and occupational exposure to styrene. Methods A total of 128 workers (85% of the total population), from three glass-reinforced plastics plants in Canada, agreed to participate in the study. Environmental and biological measures were made on the day(s) prior to the assessment of near visual acuity (National Optical Visual Chart), chromatic discrimination (Lanthony D-15 desaturated panel), and near contrast sensitivity (Vistech 6000). The analyses were performed on 81 workers with near visual acuity of at least 1 min of arc at 0.5 m. Results The subjects were relatively young [29 (SD 8) years], with little seniority [5 (SD 4) years]. Styrene exposure for 8 h ranged from 6 to 937 (first quartile 21 mg . m-' , third quartile 303 mg . m-'), depending on the job site. The end-shift concentrations of urinary mandelic acid ranged from nondetectable to 1.90 mmol . mmol creatinine-l. Significant positive relations were found between the internal and external styrene exposure measurements and color vision loss adjusted for age, alcohol consumption, and seniority in a multiple regression analysis. The multiple regression analysis also showed that the end-shift concentration of urinary mandelic acid was inversely related to contrast sensitivity at 6 and 12 cycles . degree-'. Logistic multiple regression models indicated that the end-shift concentration of urinary mandelic acid was related to the prevalences of blurred vision, tearing, and eye irritation. C O~C~U S~O~S These findings suggest that there is a positive relation between styrene exposure and early color and contrast vision dysfunction.

Besides the role of genetic factors, results on the preferential role of maternal vs paternal allergy and associations to large head circumference and placental calcifications support the hypothesis of the role of environmental factors during pregnancy on the level of cord blood IgE.

This analysis examined associations between total reduced sulfur (TRS) and hydrogen sulfide (H 2 S) levels, and hospital visits for respiratory disease among residents of Dakota City and South Sioux City, Nebraska, from January 1998 to May 2000. For reference, the association between TRS, H 2 S, and digestive diseases was also examined. Time-series analyses of daily hospital visits in the selected outcome categories and measures of TRS and H 2 S were performed using generalized additive models with a Poisson link. TRS and H 2 S levels were categorized as high if at least one of the daily 30-min rolling averages was Z30 ppb and as low if every rolling average was o30 ppb. Loess smoothers allowed for flexible modeling of the time effect and the effect of temperature and relative humidity. The measure of association used was the mean percent change in the average number of hospital visits recorded following a day with a high exposure versus a day with a low exposure. For children less than 18 years of age, a positive association was found between asthma hospital visits and 1-day lagged TRS levels. For adults, a positive association was found between asthma hospital visits and H 2 S levels on the previous day. A positive association also was found between hospital visits for all respiratory diseases, and H 2 S and TRS levels on the previous day for children but not for adults. No association was found between contaminant levels and hospital visits for all digestive diseases. These findings suggest that TRS or H 2 S levels may be associated with exacerbations of asthma or other respiratory diseases among the residents of Dakota City and South Sioux City.

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