Exposure to chemical agents in Swedish aluminum foundries and aluminum remelting plants--a comprehensive survey.

Secondary aluminum melting is mainly performed in sand, die, and static die-casting foundries and remelting plants. In seven Swedish foundries and two remelting plants, the exposure and area concentrations of total dust, metals, organic gases, and vapors were determined mainly as daily, time-weighted averages (TWAs). For most combinations of jobs and agents, the exposure levels were well below the current threshold limits suggested by the American Conference of Governmental Industrial Hygienists (ACGIH). However, high exposure levels of mineral oil mist (geometric mean [GM] = 0.6 mg/m3) were observed in the die-casting process, with a maximum of 4 mg/m3. The findings were similar for total dust (GM = 5.1 mg/m3) and crystalline quartz (GM = 0.05 mg/m3) during molding operations in the sand foundries, maximum air concentrations being 31 mg/m3 and 0.22 mg/m3, respectively. Other agents which occasionally reached high exposure levels included furfuryl alcohol (up to 23 mg/m3 during furan binder use in sand foundries), aniline (up to 2.6 mg/m3 during thermal degradation of cold-box binders), and dimethylethylamine (up to 9 mg/m3) in the cold-box process used in static die-casting and sand foundries. The average aluminum exposure levels (GM = 0.043 mg/m3) were low in all foundries, individual values not exceeding 0.94 mg/m3. The exposures to metals were below 10 percent of their threshold limits. Similarly low levels were detected of polyaromatic hydrocarbons, phenol, formaldehyde, methylenebisphenyl diisocyanate, and phenylisocyanate. In the aluminum remelting plants, a few high exposure levels of total dust (GM = 1.4 mg/m3) up to 8 mg/m3 were detected in furnace workers. Aluminum and other metals were well below 10 percent of their threshold limits, with the exception of a few high concentrations of manganese, up to 0.14 mg/m3. The between-worker variability (GSDB) in the foundries for total dust, aluminum, and oil mist were on the order of 3-4. The heterogenicity of secondary aluminum melting requires assessment of a wide variety of chemical agents. For certain exposures, technical and medical monitoring programs are still needed.

Porphyrin status in aluminum foundry workers exposed to hexachlorobenzene and octachlorostyrene.

The possible interference of hexachlorobenzene and octachlorostyrene (i.e., thermal byproducts from hexachloroethane in aluminum degassing) with porphyrin metabolism was investigated in exposed workers. Urine specimens from 9 male aluminum foundry workers (i.e., smelters) at 6 different companies and from 18 controls-matched for sex, age, residence, and socioeconomic status-were analyzed for total porphyrins and porphyrin isomers. Workers exposed to hexachlorobenzene and octachlorostyrene had a statistically significant increase in urinary total porphyrins, compared with controls (mean +/- standard deviation: 13.63 +/- 11.13 micromol/mol creatinine and 6.24 +/- 3.84 micromol/mol creatinine, respectively; p = .02). The authors attributed the results mainly to differences in excretion of coproporphyrins-notably coproporphyrin III. Erythrocyte uroporphyrinogen decarboxylase activity was similar in both groups. There was a high correlation between levels of hexachlorobenzene and octachlorostyrene, respectively, in plasma and urinary excretion of porphyrins; these findings, however, relied heavily on 1 subject for whom extreme values were obtained. The results indicated that occupational exposure to hexachlorobenzene and octachlorostyrene in aluminum degassing with hexachloroethane may affect porphyrin metabolism in a manner consistent with early secondary coproporphyrinuria-the first recognized step in the development of chronic hepatic porphyria. It was also noted that changes remained detectable some years after exposure ceased.

Cancer morbidity in workers at aluminum foundries and secondary aluminum smelters.

In a Swedish cohort of workers (n = 6,454) from seven aluminum foundries and three secondary aluminum (scrap) smelters there was no overall excess risk of cancer among male or female workers less than 85 years of age (males: 325 observed cases, standardized incidence ratio (SIR) 1.02, 95% confidence interval (CI) 0.91-1.13; females: 22 cases, SIR = 0.95, 95% CI = 0.60-1.44). In male workers, however, significantly elevated risk estimates were observed for cancer of the lung (51 cases; SIR = 1.49, 95% CI = 1.11-1.96), anorectal cancer (33 cases; SIR 2.13, 95% CI = 1.47-2.99), and sinonasal cancer (4 cases; SIR = 4.70, 95% CI = 1.28-12.01). There was no increase of urinary bladder or liver cancer. Lung cancer risks were highest in workers with a short duration of employment (< 5 years) suggesting determinants of risk related to socioeconomic factors rather than the occupational environment under study, but there were also indications of a lung cancer hazard from sand casting of aluminum for 10 years or more (SIR = 2.10, 95% CI = 1.01-3.87). The increase in anorectal cancer could not be etiologically related to occupational determinants of risk. Sand casting of aluminum aside, the cancer risk in secondary aluminum smelting seems to be lower than in primary aluminum smelting and in iron and steel founding, respectively.

Hexachlorobenzene and octachlorostyrene in plasma of aluminium foundry workers using hexachloroethane for degassing.

OBJECTIVES: To study the load of selected organochlorine compounds in the blood of aluminium foundry workers who use hexachloroethane as a degassing agent for aluminium and to measure some possible effects on internal organs. METHODS: Plasma from nine male aluminium foundry workers with past experience of use of hexachloroethane and 18 controls (two controls per exposed case) matched for residence, sex, age, and socioeconomic status was analysed for hexachlorobenzene (HCB), (P-HCB), and octachlorostyrene (P-OCS) with low resolution gas chromatography-mass spectrometry. Serum samples from the same subjects were analysed for standard kidney, pancreas, and liver function variables. Analysis of variance (ANOVA) with the triplets retained, a non-parametric test, and linear regression were used for the analysis. RESULTS: A fourfold increase of mean P-HCB was found among the exposed subjects compared with the controls (313.1 v 66.9 ng/g lipid; P < 0.01; (ANOVA model)). For P-OCS this difference was even larger (54.6 v 0.7 ng/g lipid; P < 0.01). Results were still significant (P < 0.05) with non-parametric testing. Within the exposed group there was a good correlation between the ln P-HCB (r = 0.80) and ln P-OCS (r = 0.91), respectively, with the cumulative number of years of exposure to hexachloroethane. No significant difference in kidney, pancreas, or liver function was found between the two groups. CONCLUSIONS: Aluminium degassing with hexachloroethane may increase the body burden of selected organochlorine compounds as reflected by HCB and OCS measurements. With the inherent limitations of this investigation no signs of subclinical organ toxicity were found.