Anders I. Seldén

Nephrotoxicity of uranium in drinking water from private drilled wells.

OBJECTIVES To investigate the association between uranium in drinking water from drilled wells and aspects of kidney function measured by sensitive urine tests. METHODS Three hundred and one of 398 eligible subjects (75.6%) aged 18-74 years with daily drinking water supplies from private drilled wells located in uranium-rich bedrock (exposed group) volunteered to participate along with 153 of 271 local controls (56.4%) who used municipal water. Participants responded to a questionnaire on their water consumption and general health, and provided a morning urine sample and drinking water for analysis. RESULTS The uranium content of well water samples (n=153) varied considerably (range <0.20-470 microg/l, median 6.7 microg/l, 5% >100 microg/l), while uranium levels in all samples of municipal water (n=14) were below the limit of quantification (0.2 microg/l). Urinary levels of uranium were more than eight times higher in exposed subjects than in controls (geometric means 38 and 4.3 ng/l, respectively; p<0.001), but their mean urine lead levels were not significantly different. There was a strong curvilinear correlation between uranium in drinking water and in urine (r2=0.66). Levels of albumin, beta(2)-microglobulin, protein HC as well as kappa and lambda immunoglobulin chains in urine from exposed and controls were similar. The N-acetyl-beta-d-glucosaminidase (NAG) activity was significantly lower in the exposed group vs. controls, possibly secondary to differential storage duration of samples from the two groups. Even in regression models adjusting for gender, age and smoking no association of uranium in water and the kidney function parameters was observed. Using uranium in urine in the entire study group as a marker of exposure, however, a tendency of exposure-related increases of beta(2)-microglobulin, protein HC and kappa chains were noted. This tendency was enhanced after exclusion of subjects with diabetes mellitus from the analysis. CONCLUSIONS Uranium levels in urine were strongly correlated to levels in drinking water from drilled wells. There were no clear signs of nephrotoxicity from uranium in drinking water at levels recorded in this study, but some indications of an effect were observed using uranium in urine as a measure of overall uranium exposure. The clinical relevance of these findings remains unclear.

Risk of Cancer Among Workers Exposed to Trichloroethylene: Analysis of Three Nordic Cohort Studies

BACKGROUND Trichloroethylene (TCE) is a widely used chlorinated solvent with demonstrated carcinogenicity in animal assays. Some epidemiologic studies have reported increased risk of cancer of the kidney, cervix, liver and biliary passages, non-Hodgkin lymphoma, and esophageal adenocarcinoma. METHODS We established a pooled cohort, including 5553 workers with individual documented exposure to TCE in Finland, Sweden, and Denmark. Study participants were monitored for the urinary TCE metabolite trichloroacetic acid from 1947 to 1989 and followed for cancer. Standardized incidence ratios (SIRs) were calculated based on cancer incidence rates in the three national populations. Cox proportionate hazard analyses were used for internal comparisons. Tests of statistical significance are two-sided. RESULTS Overall, 997 cases of cancer (n = 683 in men; n = 314 in women) were identified during 154 778 person-years of follow-up. We observed statistically significant elevated standardized incidence ratios for primary liver cancer (1.93; 95% confidence interval [CI] = 1.19 to 2.95) and cervical cancer (2.31; 95% CI = 1.32 to 3.75). The standardized incidence ratio for kidney cancer was 1.01 (95% CI = 0.70 to 1.42) based on 32 cases; we did not observe a statistically significant increased risk of non-Hodgkins lymphoma (SIR = 1.26; 95% CI = 0.89 to 1.73) or esophageal adenocarcinoma (SIR = 1.84; 95% CI = 0.65 to 4.65). Tobacco- and alcohol-associated cancers were not statistically significantly increased. CONCLUSIONS Our results suggest TCE exposure is possibly associated with an increased risk for liver cancer. The relationship between TCE exposure and risks of cancers of low incidence and those with confounding by lifestyle and other factors not known in our cohort require further study.

Blood lead in Swedish police officers.

BACKGROUND Shooting with lead-containing ammunition in firing ranges is a well-known source of lead exposure in adults, and police officers may be at risk of lead intoxication. More stringent national lead regulations stimulated a survey of blood lead (PbB) in Swedish police officers with regular shooting habits. METHODS Police officers considered as the most active shooters on and/or off duty responded to a questionnaire about health, lifestyle, shooting habits, and potential lead exposure. Blood samples were collected and analyzed for PbB and a multivariate regression analysis was performed. RESULTS The mean PbB in male officers (n = 75) was 0.24 mumol/L (5.0 micrograms/dL); range 0.05-0.88 mumol/L (1.0-18.2 micrograms/dL), and in female officers (n = 3) it was even lower (0.18 mumol/L; 3.7 micrograms/dL). For both sexes combined, a positive correlation (r = 0.55; P < 0.001) of PbB with the number of bullets annually fired both on and off duty was observed, and this finding remained in a multiple regression analysis including age, smoking habits, and latency from last shooting exercise. DISCUSSION In conclusion, occupational and recreational lead exposure from firing ranges still seems to be a source of lead exposure in Swedish police officers, but it no longer appears to be a health risk. Lead-free communication and well-ventilated indoor firing ranges may have been decisive for this encouraging finding.

Trichloroethylene exposure in vapour degreasing and the urinary excretion of N-acetyl-β-D-glucosaminidase

In order to elucidate the potential nephrotoxicity of low level occupational exposure to trichloroethylene (TRI), urine analysis of the tubular enzyme N-acetyl-β-dglucosaminidase (U-NAG) was included in a cross-sectional study of metal degreasers in central Sweden. Eightysix percent of 8-h TRI in air measurements were well below 50 mg/m3. Normal levels of NAG were found in morning urine samples from 29 workers compared to a historical reference group. A weak positive correlation (r = 0.48;P <0.01) was observed between U-NAG activity and the concentration of the TRI metabolite trichloroacetic acid in urine but not with other estimates of recent or long-term exposure. In conclusion, TRI does not seem to be nephrotoxic at low exposure levels.

Cobalt release from glazed earthenware: Observations in a case of lead poisoning

In a case of lead poisoning caused by a Greek jug, high levels of whole blood cobalt were also recorded. Cobalt was probably released from the underglaze dye by juice stored in the jug. The element was rapidly eliminated from the circulation and no signs of cardiotoxicity were observed in the patient. This case illustrates a possibly novel route of alimentary cobalt exposure.

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.

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.

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.

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.

Emissions of Some Organochlorine Compounds in Experimental Aluminum Degassing with Hexachloroethane

Abstract Degassing agents based on hexachloroethane (HCE) are used to remove hydrogen gas from molten aluminum, particularly in foundries and remelting plants. Previously considered fairly innocuous, recent studies of the emissions from this process have shown high yields of some toxic organochlorine compounds. To determine a wider spectrum of such compounds, a series of experimental degassings was carried out in a small foundry. Aluminum was melted at 740°C in an electric furnace equipped with a ventilated exhaust hood, and degassing was carried out with 0.12 percent (w/w) HCE. Particulate, condensed liquid, and gas phase samples of the emissions were collected in the exhaust suction duct and analyzed with gas chromatography and mass spectrometry. Chlorobenzenes, chlorophenols, chlorinated dibenzodioxins and dibenzofurans, and polyaromatic hydrocarbons, as well as hydrogen chloride, carbon monoxide, and total hydrocarbons were determined. In relation to HCE, the major organochlorine compounds in the fume...