Exceptional pharmacokinetics of trivalent chromium during occupational exposure to chromium lignosulfonate dust

The excretion of chromium in the urine of workers exposed to chromium lignosulfonate was studied. The chromium in the dust was in the trivalent (III) oxidation state, and 30% of the particles were less than 5 micron in diameter. Chromium (III) lignosulfonate dust was rapidly absorbed, and a peak of urinary excretion was seen immediately after exposure. No appreciable accumulation of chromium occurred over 3 d, as evaluated by comparison with preshift urinary chromium concentrations. The addition of ethylenediaminetetra-acetate to the urine of exposed persons greatly enhanced the capacity of chromium to traverse a dialysis membrane; the same effect was seen with chromium (III) chloride. It is concluded that chromium (III) lignosulfonate yields chromium (III), which acts pharmacokinetically like water-soluble hexavalent chromium compounds.     

Biomonitoring action levels in Finland

In Finland, biomonitoring action levels (BAL) have been set since the 1970s. There are different ways of setting these BALs. The value for blood lead is based on legislation. Exposure limits have been set on the basis of the indicative values for carbon disulfide, ethylene benzene, toluene, and phenol. The number of BALs set by the Finnish Institute of Occupational Health (FIOH) has increased year by year, and we now have BAL values for more than 36 different chemicals or chemical groups. The Institute annually publishes a booklet with the latest information about the biomonitoring tests, sample collection, and limit values. The booklet is also available in English as a web version (http:/(/)www.occuphealth.fi/tt/bio/guide346. htm).     

Risk of lung cancer among masons in Iceland.

OBJECTIVES: To estimate the risk of gastrointestinal cancer and lung cancer in a cohort of masons exposed to cement and hexavalent chromium by a follow up in the Icelandic Cancer Registry. METHODS: The cohort, 1172 men, was defined as those who had served their apprenticeship and were fully licensed as masons (cement finishers) in Iceland, were born after 1880 and were alive in 1955. The men were exposed to an aerosol of wet concrete, particularly when spraying. According to the analyses of urinary chromium the masons were exposed to hexavalent chromium. A computer file on masons was record linked to the Cancer Registry by making use of the personal identification numbers. Expected cancer incidence was calculated on the basis of number of person-years for each five-year age category during the individual calendar years of the study period and multiplied by the specific incidence for cause and calendar year for men in Iceland provided by the Cancer Registry. RESULTS: The standardised incidence ratio (SIR) for all cancers was 1.13 in the total cohort and 1.33 when allowance was made for 30 years to elapse before starting to count person years of risk. The risk for gastrointestinal cancers was not increased. The SIR for lung cancer was 1.69 in the total cohort and 1.77 when a lag of 30 years was included. The SIR for lung cancer among those born in 1920 or later was 1.86. Results from a postal questionnaire showed that fewer masons had never smoked and more masons had stopped smoking than the controls from the general population. CONCLUSION: The increased risk of lung cancer among the masons may be related to their work. The exposure information, although limited, supports the suggestion that hexavalent chromium in the cement may be the causal link, as information on the smoking habits indicate that the control for this important possible confounder is adequate.     

Urinary and blood manganese in occupationally nonexposed populations and in manual metal are welders of mild steel

Summary To obtain reference values for blood and serum manganese levels, blood specimens were collected from 29 men and 36 women. Mn in blood showed a normal distribution; its upper 97.5% limit in blood was 0.38 mol/l. Mn in serum showed a skewed distribution, which did not differ from the normal one after logarithmic transformation. The respective reference limit was 19 nmol/l. In both specimens, the levels of Mn were significantly lower in men than in women. To obtain reference values for Mn in urine, midday urine specimens were collected from 58 men and 96 women. Mn in urine also showed a skewed distribution, and the upper 97.5% limit was 38 nmol/l. The levels of Mn in blood and urine were statistically significantly higher in manual metal arc (MMA) welders of mild steel (MS) than in the reference populations. Five MMA/MS welders were subjected to a further study in which the ambient intramask Mn levels and urinary Mn excretion were monitored throughout a full working week. For two welders the correlation of Mn in urine specimens voided in the afternoon was good with the before noon Mn concentrations in the hygienic measurements; for the rest the correlation was minimal. Mn in diurnal urine specimens collected in six portions showed fluctuation if specific gravity or creatinine in urine was used to standardize for the urinary flow, but it was less evident for urinary Mn excretion rate. Our results seem to indicate that the measurement of Mn in urine or blood may be used for monitoring Mn exposure in MMA/MS welders only at the group level.These results were presented in part at the 2nd COMTOX meeting, held in Montreal in 1983     

Urinary excretion of chromium as an indicator of exposure to trivalent chromium sulphate in leather tanning

Summary Two workers exposed to trivalent chromium sulphate in a leather tannery had high concentrations of chromium in the urine. The concentration of chromium showed a workshift-related diurnal fluctuation, but it was remarkably high even after a vacation, indicating accumulation of chromium in the body. The concentrations of chromium in the workplace air, as collected on filters using standard techniques, were below 30/gmg/m³. The chromium in the air was present in the form of large droplets not collected by the standard techniques. In the blood stream, chromium was transported exclusively in the plasma. No absorption of chromium through the skin could be detected. Absorption from the gastrointestinal tract was calculated to explain the findings.     

Exposure to flame retardants in electronics recycling sites

Waste electrical and electronic equipment (WEEE) contains various hazardous substances such as flame retardants (FRs). Inhalation exposures to many FRs simultaneously among WEEE recycling site workers have been little studied previously. The breathing zone airborne concentrations of five brominated FR compounds tetrabromobisphenol-A (TBBP-A), decabromodiphenylethane (DBDPE), hexabromocyclododecane, 1,2-bis(2,4,6-tribromophenoxy)ethane, hexabromobenzene, and one chlorinated FR (Dechlorane Plus?) were measured at four electronics recycling sites in two consecutive years. In addition, concentrations of polybrominated diphenyl ethers (PBDEs) and polybrominated biphenyls were measured. The three most abundant FRs in personal air samples were PBDEs (comprising mostly of deca-BDE), TBBP-A, and DBDPE, with mean concentrations ranging from 21 to 2320 ng m(-)(3), from 8.7 to 430 ng m(-3), and from 3.5 to 360 ng m(-3), respectively. At two of the sites, the emission control actions (such as improvements in ventilation and its maintenance and changes in cleaning habits) proved successful, the mean levels of FRs in personal samples being 10-68 and 14-79% of those from the previous year or alternatively below the limit of quantification. At the two remaining sites, the reductions in FR exposures were less consistent. The concentrations reported may pose a health hazard to the workers, although evaluation of the association between FR exposure and adverse health effects is hampered by lacking occupational exposure limits. Therefore, the exposures should be minimized by adequate control measures and maintaining good occupational hygiene practice.     

Urinary cobalt as a measure of exposure in the wet sharpening of hard metal and stellite blades

 The measurement of urinary cobalt as an estimator of exposure to airborne cobalt was evaluated during the wet sharpening of hard metal and stellite blades. The following possible confounding factors were also studied: smoking habits, personal hygiene, cobalt absorption through the skin, beer drinking, and vitamin B₁₂ consumption. The study was conducted in 16 different workplaces manufacturing or maintaining blades and in laboratory experiments. Cobalt contamination and its removal from workers’ hands were studied with different hand-washing methods, and cobalt from used gloves was also analyzed. The Finnish biomonitoring action level of 600 nmol/l (35.4 μg/l) was exceeded in 4 of the 16 workplaces, and the mean concentration of urinary cobalt was 241 (8–2705) nmol/l [14.2 (0.5–160)  μg/l]. The coefficient of correlation between the cobalt concentrations in the air and in the workers’ urine was 0.753. The urinary cobalt concentration corresponding to the Finnish occupational exposure limit for airborne cobalt (0.05 mg/m³) was 686 nmol/l (40.5 μg/l). The level of personal hygiene affected the urinary cobalt concentrations, and cobalt was absorbed through the skin. Beer and vitamin B₁₂ consumption did not have any effect on the urinary levels of cobalt. The workers who smoked had higher urinary concentrations of cobalt than the nonsmoking workers. High concentrations of cobalt in coolants contaminated the workers’ skin, and hand-washing did not remove cobalt very effectively. The results indicate that urinary cobalt can be used reliably to assess workers’ exposure to airborne cobalt when wet-tip grinding processes are used. The results also show that workers’ exposure to cobalt can be reduced by improving skin protection and personal hygiene in workplaces. Received: 29 January 1996 / Accepted: 2 May 1996     

Stainless steel manual metal arc welding fumes in rats.

Forty two male Wistar rats were exposed to manual metal arc (MMA) stainless steel (SS) welding fumes generated by an automatic welding device for "nose-only" exposure. The exposure simulated an actual MMA/SS welding environment as closely as possible. For the retention study, the duration of exposure was one hour per workday for one, two, three, of four weeks and for the clearance study four weeks. The retention and clearance of the chromium, nickel, and iron found in MMA/SS welding fumes in the rats' lungs were studied as was the distribution of the metals to other organs. Instrumental neutron activation analysis (INAA) was used for the multi-element chemical activation analyses. The concentrations of chromium and nickel in the blood and the urine were determined by atomic absorption method (AAS). The retention of exogenous iron was determined by a magnetic measuring method. The results indicated that the lungs were the target organs of soluble hexavalent chromates. The half times of lung clearance for Cr, Ni, and Fe were 40 +/- 4 d, 20 +/- d, and 50 +/- 10 d. When the lung clearance curves are compared, the half times of Cr and Fe lung clearance are similar but nickel disappears faster. The distribution and clearance patterns of chromium to other organs differ from those obtained after single intravenous or intratracheal injections of alkaline chromates.     

Results of biomonitoring analyses in Biomonitoring Laboratory, Helsinki, Finland in 1997.

In 1997 a total of 4848 results of 47 different analytes from blood or urine specimens, were performed in the Finnish Institute of Occupational Health, Biomonitoring Laboratory, Helsinki, Finland. The results of these service analyses were registered in a database with additional information concerning the worker and the work place. The biomonitoring register, containing one or more results of about 30,000 workers, enables the follow-up of chemical exposure on individual or working group levels. In general, the levels of chemicals or their metabolites in biological specimens have been slowly but continuously declined in Finland during the last decade. In 1997 the decrease in the levels of heavy metals was particularly important. The most problematic organic solvent in Finland is styrene. Styrene exposures have remained in unacceptable levels in work places and still in 1997 more than a third of the workers analysed had very high concentrations of styrene metabolites in their urine. In most major analyte groups studied, there were workers whose exposure level exceeded the Finnish biomonitoring action level (BAL), and in about half of the specimens the level exceeded the upper reference limits (URL), of the non-exposed persons.     

Hand dermatitis and allergic patch test reactions caused by nickel in electroplaters

A worksite survey was conducted in all 38 Finnish electroplating plants. All workers ( n =163) who worked with nickel plating (bath workers, hangers and solution makers) were interviewed with a questionnaire about symptoms of nickel dermatitis, hand dermatitis, and about protective measures, atopy, etc. Patch testing with nickel sulfate was done with the TRUE Test^TM method. All the workers, 94 men and 69 women, answered the questionnaire. The mean age of women was 41.1 years, and of men 43.1 years, respectively. Men had longer occupational exposure to nickel (14 years) than women (10 years). Most workers used protective gloves. 35% of women and 30% of men reported present or past hand dermatosis. 19% reported a history of atopic dermatitis. 15% of women ( n = 8) and 4% ( n = 2) of men had an allergic patch test reaction to nickel sulfate. 70% of those with an allergic patch test reaction to nickel reported past or present hand eczema. The prevalence of nickel allergy among the electroplaters was similar to that of patients in patch test clinics in Finland. An allergic patch test reaction to nickel sulfate does not necessarily oblige an electroplater to change jobs.