Urine phthalate determinations as an index of occupational exposure to phthalic anhydride and di(2-ethylhexyl)phthalate.

Although it has been estimated that over 600 000 workers in the United States are exposed to di(2-ethylhexyl)phthalate (DEHP), an animal carcinogen, and that over 100 000 are exposed to phthalic anhydride (PA), few data are available on levels of phthalates in biological fluids of these workers. For a determination of occupational exposure to PA and DEHP at a plant manufacturing DEHP from PA and 2-ethylhexanol, air samples were taken for PA and DEHP, and pre- and postshift urine samples were collected for the determination of total phthalates. Urine samples were obtained from 48 workers in jobs with high exposure to phthalates and from 47 workers in jobs with low exposure. The airborne concentrations of DEHP ranged from 20 to 4 110 micrograms/m3, and the concentrations of PA ranged from 4 to 203 micrograms/m3. The most heavily exposed workers had the highest mean postshift urine phthalate concentration (geometric mean 7.6 nmol/ml) (p = 0.015), and also the greatest mean increase (4.4 nmol/ml) in preshift to postshift urine phthalate levels. Twofold increases over the shift in urine phthalate concentration and postshift phthalate levels of greater than 10 nmol/ml were observed in 8 (25%) of 32 chemical operators, but in none of 52 other workers. These data suggest that measurement of urine phthalate levels may have utility for monitoring the exposure of workers manufacturing or using PA.

The efficacy of a population-based comparison group in cross-sectional occupational health studies.

The availability and the choice of appropriate comparison groups are essential for valid occupational epidemiologic studies. Too often, however, adequate comparison groups cannot easily be found within a workplace environment or extracted from the general population. An evaluation of the efficacy of using a pool of comparison subjects from the health and Nutrition Examination Survey (HANES) was performed on data gathered by the National Institute for Occupational Safety and Health in 1979. Comparison groups from the HANES pool were derived for 246 workers at four different commercial/industrial facilities in the Niagara Falls, New York, area and the comparability between the groups was assessed for several demographic, behavioural, and biomedical variables. The HANES groups exhibited a high degree of comparability with regard to most variables, excluding ancestry. The HANES pool may serve as a useful source of subjects to allow for the comparison of disease rates where occupational exposure is the key distinguishing feature between groups.

Occupational exposure to arsine. An epidemiologic reappraisal of current standards.

In an evaluation of chronic occupational exposure to arsine (AsH3), an epidemiologic survey was conducted at a lead-acid battery manufacturing plant. Personal (breathing zone) air samples were obtained for the measurement of exposure to arsine and particulate arsenic (As), and area air samples were also collected for the determination of arsenic trioxide (As2O3) vapor concentrations. For the quantification of arsenic absorption, total arsenic content was determined in duplicate 24-h urine samples. Arsine in 177 breathing-zone air samples ranged from nondetectable to 49 micron/m3. The highest levels were found in the battery formation area, where arsine is generated by the reaction of battery acid with lead-arsenic alloy. Exposures to particulate arsenic (maximum 5.1 micron/m3) and to As2O3 (maximum (20.5%) of 39 production workers had urinary arsenic concentrations (corrected to a specific gravity of 1.024) of 50 micron/1 (0.67 mumol/1) or above, indicating increased arsenic absorption. None of eight office staff had elevated urinary arsenic levels. A close correlation was found between urinary arsenic concentration and arsine exposure (N = 47; r = 0.84; p = 0.0001). Arsine levels above 15.6 micron/m3 were associated with urinary arsenic concentrations in excess of 50 micron/1 (0.67 mumol/1). No correlation was found between urinary arsenic content and exposures to particulate arsenic or to As2O3. Consumption of neither seafood, red wine, tobacco, nor contaminated drinking water accounted for urinary arsenic excretion. It was concluded that the current arsine exposure standard, 200 micron/m3, fails to prevent chronic increased absorption of trivalent arsenic from the inhalation of arsine.

Beryllium sampling methods.

Three sampling methods for airborne beryllium are compared to validate observations made in a 1973 National Institute for Occupational Safety and Health (NIOSH) industrywide study of the beryllium industry which indicated that, in general, the three methods yielded different results for samples taken in the same environment. Under NIOSH contract a beryllium production facility was sampled in 1974 by the Atomic Energy Commission (AEC) personal total and personal respirable sampling methods over a period of one year. All samples were analyzed by atomic absorption spectroscopy. Statistical analysis of the resulting data by NIOSH confirms the observations made in the 1973 study that samples collected by the three methods produced different results. No reliable relationship was found to exist which would permit conversion of the result obtained by one method to a result obtained by either of the alternate methods. It appears that, in general, for large numbers of samples taken under the same sampling conditions, the values determined by the personal respirable sampling method will be lower than those obtained by the AEC method and the values determined by the personal total sampling method will be greater.