A regional comparison of children's blood cadmium, lead, and mercury in rural, urban and industrial areas of six European countries, and China, Ecuador, and Morocco.

OBJECTIVES: The authors aimed to evaluate whether blood cadmium (B-Cd), lead (B-Pb) and mercury (B-Hg) in children differ regionally in 9 countries, and to identify factors correlating with exposure. MATERIAL AND METHODS: The authors performed a cross-sectional study of children aged 7-14 years, living in 2007-2008 in urban, rural, or potentially polluted ("hot spot") areas (ca. 50 children from each area, in total 1363 children) in 6 European and 3 non-European countries. The authors analyzed Cd, Pb, and total Hg in blood and collected information on potential determinants of exposure through questionnaires. Regional differences in exposure levels were assessed within each country. RESULTS: Children living near industrial "hot-spots" had B-Cd 1.6 (95% CI: 1.4-1.9) times higher in the Czech Republic and 2.1 (95% CI:1.6-2.8) times higher in Poland, as compared to urban children in the same countries (geometric means [GM]: 0.13 µg/l and 0.15 µg/l, respectively). Correspondingly, B-Pb in the "hot spot" areas was 1.8 (95% CI: 1.6-2.1) times higher than in urban areas in Slovakia and 2.3 (95% CI: 1.9-2.7) times higher in Poland (urban GM: 19.4 µg/l and 16.3 µg/l, respectively). In China and Morocco, rural children had significantly lower B-Pb than urban ones (urban GM: 64 µg/l and 71 µg/l, respectively), suggesting urban exposure from leaded petrol, water pipes and/or coal-burning. Hg "hot spot" areas in China had B-Hg 3.1 (95% CI: 2.7-3.5) times higher, and Ecuador 1.5 (95% CI: 1.2-1.9) times higher, as compared to urban areas (urban GM: 2.45 µg/l and 3.23 µg/l, respectively). Besides industrial exposure, traffic correlated with B-Cd; male sex, environmental tobacco smoke, and offal consumption with B-Pb; and fish consumption and amalgam fillings with B-Hg. However, these correlations could only marginally explain regional differences. CONCLUSIONS: These mainly European results indicate that some children experience about doubled exposures to toxic elements just because of where they live. These exposures are unsafe, identifiable, and preventable and therefore call for preventive actions. Int J Occup Med Environ Health. 2023;36(3):349-64.

Platinum, palladium, rhodium, molybdenum and strontium in blood of urban women in nine countries.

BACKGROUND: There is little reliable information on human exposure to the metals platinum (Pt), palladium (Pd) and rhodium (Rh), despite their use in enormous quantities in catalytic converters for automobile exhaust systems. OBJECTIVES: To evaluate blood concentrations of Pt (B-Pt), Pd (B-Pd) and Rh (B-Rh) in women from six European and three non-European countries, and to identify potentially influential factors. In addition, molybdenum (Mo) and strontium (Sr) were analysed. METHODS: Blood from 248 women aged 47-61 was analysed by high resolution inductively coupled plasma mass spectrometry under strict quality control. RESULTS: The medians were: B-Pt 0.8 (range <0.6-5.2), B-Pd <5 (<5-9.3), B-Rh <0.4 (<0.4-3.6)ng/L and B-Mo 2.0 (0.2-16) and B-Sr 16.6 (3.5-49) µg/L. Two women with highly elevated B-Pt (242 and 60ng/L), previously cancer treated with cis-platinum, were not included in the data analysis. All elements varied geographically (2-3 times) (B-Pd P=0.05; all other elements P<0.001); variations within each area were generally 5-10 times. Traffic was not associated with increased concentrations. CONCLUSIONS: General population blood concentrations of Pt, Pd and Rh are within or below the single digit ng/L range, much lower than in most previous reports. This is probably due to improved analytical performance, allowing for more reliable information at ultra-trace levels. In general, Mo and Sr agreed with previously reported concentrations. All elements showed geographical and inter-individual variations, but no convincing relationships with self-reported traffic intensity were found. Pt from the antineoplastic drug cis-platinum is retained in the body for years.

Late effects of low blood lead concentrations in children on school performance and cognitive functions.

BACKGROUND: Although it is known that lead is a neurotoxin that negatively impacts cognitive functions at low blood concentrations (B-Pb), little is known about the impact of early exposure on later cognitive functions. OBJECTIVES: This study assesses the effects of very low lead exposure in early childhood on teenage cognitive performance. METHODS: Using data collected between 1978 and 2007, we analyzed B-Pb (median 30 µg/L; six-fold decrease over time) in 3176 Swedish children (age 7-12). School performance in grade 9 (age 16; boys and girls) and over-all IQs measured during conscription examinations (age 18-19; mainly boys) were obtained from registers. In multivariate models, potential confounders (age at blood sampling, sex, parents' education, family economy, and country of birth of child and parents) and effect modifiers (socioeconomic; father's IQ at conscription examination) were included. RESULTS: There were statistically significant adjusted negative associations between school performance (Grades up to 1991: P<0.0001; Merits 1992-2007:P<0.0001) and IQ (P=0.03) and B-Pb. The dose-response relationships were non-linear. Effects were more pronounced for B-Pb≤50 µg/L than for higher levels. In the B-Pb range 5-50 µg/L, the average IQ loss corresponded to about 5 IU. There was no significant effect modification associated with socioeconomic factors. CONCLUSIONS: Lead causes neurotoxic effects at very low exposures (B-Pb<50 µg/L) in childhood and these effects remain for many years.

Cadmium, mercury and lead in the blood of urban women in Croatia, the Czech Republic, Poland, Slovakia, Slovenia, Sweden, China, Ecuador and Morocco.

OBJECTIVES: The aim of the study was to make an international comparison of blood levels of cadmium (B-Cd), lead (B-Pb) and mercury (B-Hg) of women in seven European, and three non-European cities, and to identify determinants. MATERIALS AND METHODS: About 50 women (age: 46-62) from each city were recruited (totally 480) in 2006-2009. Interview and questionnaire data were obtained. Blood samples were analysed in one laboratory to avoid interlaboratory variation. RESULTS: Between the European cities, the B-Pb and B-Cd results vary little (range of geometric means: 13.5-27.0 µg/l and 0.25-0.65 µg/l, respectively); the variation of B-Hg was larger (0.40-1.38 µg/l). Between the non-European cities the results for B-Pb, B-Cd and B-Hg were 19.2-68.0, 0.39-0.99 and 1.01-2.73 µg/l, respectively. Smoking was a statistically significant determinant for B-Cd, while fish and shellfish intakes contributed to B-Hg and B-Pb, amalgam fillings also contributed to B-Hg. CONCLUSIONS: The present results confirm the previous results from children; the exposure to lead and cadmium varies only little between different European cities suggesting that other factors than the living area are more important. The study also confirms the previous findings of higher cadmium and lead levels in some non-European cities. The geographical variation for mercury is significant.

Blood cadmium, mercury, and lead in children: an international comparison of cities in six European countries, and China, Ecuador, and Morocco.

Children's blood-lead concentration (B-Pb) is well studied, but little is known about cadmium (B-Cd) and mercury (B-Hg), in particular for central Europe. Such information is necessary for risk assessment and management. Therefore, we here describe and compare B-Pb, B-Cd and B-Hg in children in six European, and three non-European cities, and identify determinants of these exposures. About 50 school children (7-14 years) from each city were recruited (totally 433) in 2007-2008. Interview and questionnaire data were obtained. A blood sample was analyzed: only two laboratories with strict quality control were used. The European cities showed only minor differences for B-Cd (geometric means 0.11-0.17 µg/L) and B-Pb (14-20 µg/L), but larger for B-Hg (0.12-0.94 µg/L). Corresponding means for the non-European countries were 0.21-0.26, 32-71, and 0.3-3.2 µg/L, respectively. For B-Cd in European samples, traffic intensity close to home was a statistically significant determinant, for B-Hg fish consumption and amalgam fillings, and for B-Pb sex (boys higher). This study shows that European city children's B-Cd and B-Pb vary only little between countries; B-Hg differs considerably, due to varying tooth restoration practices and fish intake. Traffic intensity seemed to be a determinant for B-Cd. The metal concentrations were low from a risk perspective but the chosen non-European cities showed higher concentrations than the cities in Europe.