Multi-component assessment of worker exposures in a copper refinery : Part 2. Biological exposure indices for copper, nickel and cobalt

Biomonitoring for workplace exposure to copper and its compounds is currently not interpretable

This paper sets out to explore the requirements needed to recommend a useable and reliable biomonitoring system for occupational exposure to copper and its inorganic compounds. Whilst workplace environmental monitoring of copper is used to measure ambient air concentrations for comparison against occupational exposure limits, biological monitoring could provide complementary information about the internal dose of workers, taking into account intra-individual variability and exposure from all routes. For biomonitoring to be of reliable use for copper, a biomarker and the analytical ability to measure it with sufficient sensitivity must be identified and this is discussed in a range of matrices. In addition, there needs to be a clear understanding of the dose-response relationship of the biomarker with any health-effect (clinical or sub-clinical) or, between the level of external exposure (by any route) and the level of the copper biomarker in the biological matrix being sampled, together with a knowledge of the half-life in the body to determine accurate sampling times. For many biologically non-essential metals the requirements for reliable biomarkers can be met, however, for 'essential' metals such as copper that are under homeostatic control, the relationship between exposure (short- or long-term) and the level of any copper biomarker in the blood or urine is complex, which may limit the use and interpretation of measured levels. There are a number of types of biomarker guidance values currently in use which are discussed in this paper, but no values have yet been determined for copper (or its inorganic compounds) due to the complexity of its essential nature; the US The American Conference of Governmental Industrial Hygienists (ACGIH) has however indicated that it is considering the development of a biological exposure index for copper and its compounds. In light of this, we present a review of the reliability of current copper biomarkers and their potential use in the occupational context to evaluate whether there is value in carrying out human biomonitoring for copper exposure. Based on the available evidence we have concluded that the reliable use of biomonitoring of occupational exposure to copper and its application in risk assessment is not possible at the present time.

Immune response and oxidative stress in workers of a copper concentration factory

Purpose

The main occupational safety measure in factories is monitoring workers exposed to various types of contaminations. The main environmental concern of governments about copper industries is emission of dust, metals, metal compounds and volatile organic compounds in air. The purpose of this paper is to evaluate the immune system status of workers in a copper concentration factory in Iran by placing the emphasis on oxidative stress biomarkers.

Design/methodology/approach

A comparative cross-sectional study was performed on 40 workers of the copper concentration factory and 40 unexposed individuals. White blood cell count, plasma interleukin 2 and 4, oxidative burst of neutrophils, oxidative damages of DNA and RNA, lipid and protein, total antioxidant capacity of plasma, and antioxidant enzymes activities were measured.

Findings

A significant decrease in the white blood cell count and interleukin 2 and an increase in the interleukin 4 were observed in the workers and these changes represented the possibility of inflammation and weakening of the immune system. The elevation of oxidative damages, total antioxidant capacity and the activity of antioxidant enzymes are indicative of the change in oxidative stress status.

Originality/value

The oxidative stress induction and immune system changes might be useful biomarkers in screening and surveillance for occupational hazard. More studies are needed to find out the type and the concentration of pollutants and to evaluate the protective effects of natural antioxidants.

Body burdens, sources and interrelations of selected toxic and essential elements among the nine Cree First Nations of Eeyou Istchee, James Bay region of northern Quebec, Canada

BACKGROUND

this article constitutes a report on the comprehensive Nituuchischaayihtitaau Aschii multi-community environment-and-health study conducted among the Cree peoples (Eeyouch) of northern Quebec, Canada.

OBJECTIVES

to interpret observed concentrations of a suite of chemical elements in a multi-media biological monitoring study in terms of sources and predictors.

METHODS

the concentrations of 5 essential and 6 toxic chemical elements were measured in whole blood, and/or in urine or hair by ICP-MS. Concentrations of essential elements are compared to those considered normal (i.e., required for good health) and, when toxic, deemed acceptable at specified concentrations in public health guidelines. Their dependence on age, sex, the specific community lived-in and diet were explored employing multivariate analysis of variance (MANOVA) involving new variables generated by principle component analysis (PCA) and correspondence analysis (CA).

RESULTS

the 5 most prominent PCA axes explained 67.7% of the variation, compared to 93.0% by 6 main CA factors. Concentrations of the essential elements in whole blood (WB) and iodine(i) and arsenic (As) in urine were comparable to those reported in the recent Canadian Health Measures survey and are assigned to dietary sources. By contrast, WB cadmium (Cd) was elevated even when smoking was considered. Mercury (Hg) concentrations in WB and hair were also higher in adults, although comparable to those observed for other indigenous populations living at northern latitudes. Fish consumption was identified as the prominent source. Of the 5 coastal communities, all but one had lower Hg exposures than the four inland communities, presumably reflecting the type of fish consumed. Use of firearms and smoking were correlated with WB-lead (Pb). The concentrations of both Hg and Pb increased with age and were higher in men, while WB-Cd and smoking prevalence were higher in women when considering all communities. Hg and Pb were low in children and women of reproductive age, with few exceedances of health guidelines. Although individuals with T2D had somewhat lower WB-Cd, there is some indication that Cd may potentiate renal dysfunction in this subgroup. Plots of selected CA axes grouped those elements expected to be in a normal diet and distinguished them from those with well-known unique sources (especially Hg and As in hair; and Hg, Pb and Cd in WB).

CONCLUSIONS

the use of multiple biological media in conjunction with the complementary PCA and CA approaches for constructing composite variables allowed a more detailed understanding of both the sources of the essential and toxic elements in body fluids and the dependencies of their observed concentrations on age, sex, community and diet.

Evaluation of atmospheric inputs as possible sources of antimony in pregnant women from urban areas

Antimony and copper are common components of brake linings. The occurrence of these two metals in urban atmospheric aerosols has been related to vehicular use. Urine samples (n=466) taken during the 32nd week of pregnancy were analyzed for Sb and Cu in pregnant women from an urban area (Sabadell, Catalonia, Spain). The geometric mean levels were 0.28 and 13 μg/g creatinine, respectively. Positive significant associations between urine concentrations of Sb and seasonality, intensity of physical exercise, working activities and traffic intensity at their home streets were observed. Cu showed the same trends but without statistical significance. In both cases, the estimated dietary ingestion of these two metals was larger than the inhalation inputs but the difference was much higher for Cu than for Sb. While Sb has no dietary role, Cu is an essential element which is also incorporated into humans through diet. The results suggest that inhalation of atmospheric particles may also constitute a source of Sb in pregnant women and general population of urban areas.

Determinants of metals exposure to metalworking fluid among metalworkers in Taiwan

Metalworking fluids (MWFs) aerosols are known to have carcinogenic potential to humans that monitoring of MWFs is necessary to reduce risks. This study summarizes biological monitoring and occupational hygiene findings from a survey of metalworkers exposed to heavy metals in a socket manufacturing plant. Manganese, nickel, iron, copper, chromium, and zinc were selected for target metals. Air samples were collected and postshift urines were obtained from the thread cutting workers and punch press machine operators. There were positive correlations between the airborne concentrations of Cr, Mn, as well as Zn and the corresponding levels of urine for the exposed groups. Therefore, the integration of biological and environmental monitoring is feasible for Cr, Mn, and Zn. The results indicated significant correlations between the levels of Cu, Cr, Fe, as well as Zn from the air and sump MWFs at thread cutting and punch press sites.

Human biomonitoring in the Arctic. Special challenges in a sparsely populated area

Human biomonitoring in the Arctic creates certain challenges. Important exposure and health issues are: the various mixtures of contaminants found in the Arctic; long-range transport sources; accumulation in the traditional food chain; unique small populations; toxicant-nutrient interactions; genetic susceptibility factors; and multiple non-dietary confounding factors (especially lifestyle issues of the indigenous population groups). Through the Arctic Monitoring and Assessment Programme (AMAP), systematic biomonitoring studies have been implemented since the mid-1990 s. Some concentrations of organic contaminants and toxic metals in human body fluids and tissues have raised concern, leading to the establishment of several mother-and-child cohorts. The aim of these efforts is to clarify possible health effects of the contaminants, especially in relation to pregnancy outcome and child development. The studies are ongoing and will lead to improved knowledge and public health advisories to reduce the risk of adverse health effects for the coming generations. Some of the indigenous population groups of Greenland, Canada, Alaska and Russia, as well as occupationally exposed populations in the Russian Arctic have had special attention during the last 15 years. The biomonitoring programs have resulted in public health interventions and dietary advice for vulnerable groups, like children and pregnant women. The sparsely populated areas where the studies are implemented create special ethical challenges to avoid research fatigue in the small population groups under surveillance. The research teams have a special responsibility to create communication strategies in close cooperation with the local authorities and build all research into a cultural context.

Minor heavy metal: A review on occupational and environmental intoxication

Heavy metal is widely used in industries and presents as a problematic environmental pollution. Some heavy metals, especially lead and mercury, are well described for their occupational and environmental intoxication whereas the other minor heavy metals are less concerned. In this article, the author will present the details of occupational and environmental minor heavy metal intoxication. This review focuses mainly on aluminum, tin, copper, manganese, chromium, cadmium and nickel.

Changes in maternal blood concentrations of selected essential and toxic elements during and after pregnancy

The objective of this study was to investigate changes in the levels of toxic and essential elements in maternal blood during pregnancy and subsequently. A subset of 211 pregnant women from the North Norwegian Mother-and-Child Study was included. Blood samples were collected during the 2(nd) trimester (P1) and postpartum (day 3, P2; and 6 weeks, P3) in different regions of northern Norway, and were analyzed for a suite of 10 selected elements. The latter feature three general but distinct concentration patterns across the three collection periods, namely: progressive increase [Group 1: As, Cd (non-smokers only), Mn, Pb and Zn]; V-shaped, with a minimum at P2 [Group 2: Cd (smokers), Hg, Mo and Se]; and downward V, with a maximum at P2 [Group 3: Co and Cu]. These trends are interpreted in the context of underlying metabolic, hematological and physiological changes that occur in mothers, as well the biochemistry and accumulation preferences of these elements within the whole blood compartment and breast milk. Implications for biomonitoring strategies are discussed. In a multivariable analysis of the P1 data, fish consumption was a robust positive predictor for Hg (p < 0.02), As (p < 0.01) and Se (p ≤ 0.001) blood concentrations, multivitamin intake for Se (p < 0.001), and parity for Co (p < 0.002); age reached significance only for Hg (p < 0.001). An inverse association was observed between parity and Hg (p < 0.05). For the other elements, predictor patterns were not evident.

Toxic and essential elements in blood from delivering women in selected areas of São Paulo State, Brazil

This study was designed to evaluate the degree of environmental contamination and possible exposure of pregnant women to toxic elements in seven selected areas of São Paulo State, Brazil. The overall median concentration of Mo in maternal blood was 0.53 μg L⁻¹, highly significant differences found between sites (p < 0.0001). Cd was found to be low overall - 0.09 μg L⁻¹ (0.01-0.58 μg L⁻¹) - with mothers from the Coastal and Rural 1 sites having the highest levels (p < 0.016).Median Hg concentration was 0.60 μg L⁻¹ (0.06 μg L⁻¹-4.35 μg L⁻¹); median Pb level was 16.2 μg L⁻¹ (3.5-57.7 μg L⁻¹) and no differences between sites were observed for both metals. Median Mn level was 16.7 μg L⁻¹ (7.0-39.7 μg L⁻¹), being highest in Urban 2 site (p < 0.016). Concentrations of maternal Co were found to range between 0.06 μg L⁻¹ and 1.1 μg L⁻¹ (median 0.25 μg L⁻¹) and As level was 0.60 μg L⁻¹ (0.10-3.8 μg L⁻¹) overall, with no statistical significance between sites for Co and As. Median Se concentrations were found to be 64 μg L⁻¹ (36-233 μg L⁻¹), with the highest median levels found in Urban 3 site; site differences were statistically significant (p < 0.0001). Correlation for each element (between paired maternal and cord blood) was measured only in Rural site 1; significant correlation was shown for Hg, Pb, Mn and Co (p < 0.05). These findings may be interpreted as indicating low environmental contamination in São Paulo State, Brazil. These findings could also indicate that pregnant women have little or no contact with pollutants, possibly due to awareness campaigns carried out by public health practitioners.

Maternal nickel exposure and congenital musculoskeletal defects

OBJECTIVE

To investigate whether women occupationally exposed to nickel in early pregnancy are at elevated risk of delivering a newborn with a malformation or deformation of the musculoskeletal system (ICD-10: Q65-Q79).

METHODS

Data about the newborn, maternal occupation and workplace were obtained using the Kola Birth Register (KBR). Each record in the KBR was assigned a categorical nickel (Ni) exposure rating according to the occupation the delivering woman had at the time of becoming pregnant. This was achieved by using as a guideline the water-soluble Ni subfraction of the inhalable aerosol fraction obtained by personal monitoring for nickel- and copper-refinery workers or/and measured urinary-Ni concentrations. The reference population was delivering women from the source population with background exposure level. In total, the study population consisted of 22,965 births.

RESULTS

Three hundred and four infants (13.3/1,000 births; 95% confidence interval (CI): 11.9-14.7) were diagnosed with isolated musculoskeletal defect(s) at birth. The adjusted odds ratio for the association between the maternal exposure to Ni and this outcome was 0.96 (95% CI: 0.76-1.21) per unit increase in exposure category.

CONCLUSION

The incidence of defects in the musculoskeletal system at birth was high, especially for feet deformities, but we found no effect of maternal exposure to water-soluble Ni on the risk of delivering a newborn with a defect. However, the incidence among women working in the copper refinery was higher than in the other employment groups.

Spontaneous abortions among nickel-exposed female refinery workers

A case-control study to investigate whether women employed in nickel-exposed work areas in early pregnancy are at elevated risk of spontaneous abortion (SA). Data about pregnancy outcome and maternal factors were obtained about each delivery and SA from women in selected work places. Each pregnancy record was assigned a categorical nickel (Ni) exposure rating according to the women's occupations at pregnancy onset. The guidelines were the water-soluble Ni subfraction of the inhalable aerosol fraction obtained by personal monitoring for nickel- and copper-refinery workers or/and measured urinary-Ni concentrations. The unadjusted odds ratio for the association between the maternal exposure to Ni and an SA for Ni-exposed women was 1.38 (95% confidence interval: 1.04-1.84), and the adjusted was 1.14 (0.95-1.37). In conclusion, there was no statistical association between maternal occupational exposure to water-soluble Ni in early pregnancy and the risk of self-reported SA. The findings do not exclude the possibility of a weak excess risk, or a risk in the first weeks of pregnancy.