Avaliação dos fatores de risco relacionados à exposição ao chumbo em crianças e adolescentes do Rio de Janeiro

A comprehensive analysis of children's blood lead levels in Latin America and the Caribbean over the last eight years: Progress and recommendations

In 2017 we published a review on blood lead levels (BLL) in children from Latin America and the Caribbean (LAC) for data available up to 14th of March 2014 and recommended the identification and control of "lead hot spots". In the present study, an evaluation of progress toward reducing BLL in the region was carried out. A systematic review of the latest literature on lead exposure in the LAC region held on the PubMed, Web of Science and LILACS databases (January 2014 to March 2022) was conducted using the PRISMA methodology. Only original papers published in peer-reviewed English, Spanish, or Portuguese journals were eligible. A total of 558 papers were retrieved, 77 of which met the selection criteria and 31 (40.25 %) were carried out in Mexico. The prevalence of children with BLL above 10 μg. dL-1 was 22.08 % in the previous review versus 6.78 % in the current study. In the present review, the prevalence of children with BLL above 5 μg. dL-1 was 29.62 %, and only one study reported a BLL prevalence rate between 3.3 and 5 μg. dL-1. The highest BLLs were associated with well-known sources or occupational exposures. The number of countries (n = 13) that published data on BLL in children was lower compared to the previous review (n = 16). Most studies were conducted in areas with known lead exposure sources, similar to the earlier review. The percentage of children at risk of lead poisoning in the region remains unknown because few studies have published data on environmental exposure levels and most samples were relatively small. The recommendation to identify and control sources of lead exposure was maintained, while further suggestions for establishing a systematic public health surveillance system for lead were proposed to help reduce the knowledge gap and inform public health policy-making in LAC.

Prevalence of metal levels above the reference values in a municipality affected by the collapse of a mining tailings dam: Brumadinho Health Project

ABSTRACT Objective: To describe the prevalence of levels of arsenic, cadmium, mercury, lead and manganese above the reference values (RV) in the population of Brumadinho, after the rupture of the mining tailings dam and to verify the factors associated with these levels. Methods: Baseline study of a prospective cohort, in a representative sample of 3,080 residents (aged 12 and over) in Brumadinho, Minas Gerais. Exploratory variables (age, sex, skin color, household income, smoking and place of residence) were collected using a questionnaire and the levels of As, Cd and Hg in urine and Pb and Mn in blood were evaluated using the technique of inductively coupled plasma mass spectrometry. The distribution of prevalence of levels above the reference for metals was made, according to the exploratory variables. Multiple logistic regression analyzes were used to investigate the association between altered levels of metals and characteristics evaluated. Results: Concentrations above RV were found in 38.08% of the population for Mn, 33.37% for As, 5.04% for Pb, 0.76% for Hg and 0.17% for Cd. There was a significant association between age group and levels of Mn and Pb; and between place of residence and As level. Conclusion: The results show a high prevalence of levels above the reference for Mn, As and Pb, with small differences in relation to the other variables, suggesting that it is an exposure distributed throughout the municipality.

Blood lead and cadmium levels in preschool children and associated risk factors in São Paulo, Brazil

In Brazil, there are scarce data on lead (Pb) and cadmium (Cd) contamination, especially for more vulnerable populations such as preschool children. In this paper, we answer two questions: (1) What are the exposure levels of lead and cadmium in preschool children, in Sao Paulo, Brazil? and (2) What are the risk factors associated with this exposure? This cross-sectional study included 50 day care centers (DCCs), totaling 2463 children aged 1-4 years. Venous blood samples were analyzed by ICP-MS. Questionnaires were administered to the parents. Multiple logistic regression models were used to identify associations between blood lead levels (BLLs) and blood cadmium levels (BCLs) and potential risk factors. The geometric mean for BLLs was 2.16 μg/dL (95% CI: 2.10-2.22 μg/dL), and the 97.5th percentile was 13.9 μg/dL (95% CI: 10.0-17.3 μg/dL). For cadmium exposure, the geometric mean for BCLs was 0.48 μg/L (95% CI: 0.47-0.50 μg/L), and the 95th percentile was 2.57 μg/L (95% CI: 2.26-2.75 μg/L). The DCCs' geographic region was associated with high BLLs and BCLs, indicating hot spots for lead and cadmium exposures. In addition, it was found that the higher the vehicles flow, the higher were the BLLs in children. Red lead in household gates was also an important risk factor for lead exposure. Comparing these results with the findings of the Fourth National Report on Human Exposure to Environmental Chemicals by CDC-2013, it was found that in Brazilian preschool children the BLLs are almost three times higher (97.5th percentile) and the BCLs are almost twelve times higher (95th percentile) than those in U.S. children. This information is essential to formulate public health policies.

What are the blood lead levels of children living in Latin America and the Caribbean?

INTRODUCTION

Information on the prevalence of lead exposure is essential to formulate efficient public health policies. Developed countries have implemented successful public policies for the prevention and control of lead poisoning. In the United States, Canada, Japan and the European Union, for instance, periodically repeated prevalence studies show that blood lead levels (BLLs) in children have decreased overall. Although BLL of Latino children in the U.S. have also dropped in recent years, the geometric mean remains higher than that of white children. Little is known about lead exposure in children in Latin America and the Caribbean (LAC). In this review, we responded to two questions: What is currently known about lead sources and levels in children in LAC? Are there public policies to prevent children's exposure to lead in LAC?

METHOD

We conducted a literature review covering the period from January 2000 to March 2014 in the PubMed and Lilacs databases to obtain English, Portuguese and Spanish language studies reporting the prevalence of BLLs in children aged 0-18years living in LAC countries. No specific analytical method was selected, and given the scarcity of data, the study was highly inclusive.

RESULTS

Fifty-six papers were selected from 16 different LAC countries. The children's BLLs found in this review are high (≥10μg/dL) compared to BLLs for the same age group in the U. S. However, most studies reported an association with some type of "lead hot spot", in which children can be exposed to lead levels similar to those of occupational settings. Only Peru and Mexico reported BLLs in children from population-based studies.

CONCLUSIONS

Most BLLs prevalence studies carried out in LAC were in areas with known emission sources. The percentage of children at risk of lead poisoning in LAC is unknown, and probably underestimated. Thus, there is an urgent need to establish public health policies to quantify and prevent lead poisoning, specifically by prioritizing the identification and control of "hot spots".

Associated factors for higher lead and cadmium blood levels, and reference values derived from general population of São Paulo, Brazil

Human activities are associated with emissions of various metals into the environment, among which the heavy metals lead and cadmium stand out, as they pose a risk to human life even at low concentrations. Thus, accurate knowledge of the levels of these metals exhibited by the overall population, including children, is important. The aim of this study was to estimate the concentrations of lead and cadmium in the blood of adults, adolescents and children residing in the city of São Paulo, assess factors associated with higher lead and cadmium blood levels, and to establish reference values for this population. The study sample consisted of 669 adults over 20 years old, 264 adolescents aged 12 to 19 years old and 391 children under 11 years old from both genders. The samples were collected at the end of 2007 and during 2008 in different city zones. Higher blood lead concentration was significantly associated with gender, smoking, offal intake, area of residence and age. The blood cadmium concentration was significantly associated with gender, smoking, consumption of distilled beverages and age. The reference values of lead and cadmium established for adults above 20 years old were 33 μg/L and 0.6 μg/L, respectively, for adolescents (12 to 19 years old) were 31 μg/L and 0.6 μg/L, respectively and for children under 11 years old were 29 μg/L and 0.2 μg/L, respectively. The results of this study indicate that the exposure levels of the investigated population to lead and cadmium are low.

Histopathological biomarkers in juvenile silver catfish (Rhamdia quelen) exposed to a sublethal lead concentration

The aim of this study was to determine the 96-h lethal concentration (96-h LC50) of lead (Pb) in silver catfish, Rhamdia quelen, and to determine histopathological biomarkers in fish exposed for 96-h to a sublethal concentration at 25% of the LC50. The 96-h LC50 was 108 mgl(-1). In gills, the length and thickness of lamella and thickness of the filament epithelium were significantly higher in fish exposed to Pb for 48-h than in control fish whereas the interlamellar distance decreased. In the liver, the area occupied by lipid droplets and size of hepatocytes showed significantly higher values after 24-h of exposure. The percentage of abnormal renal tubules was higher in fish exposed to Pb, exhibiting a time-dependent increase. These variations in histopathological biomarkers permit the definition of the overall response of R. quelen to Pb and the potential usefulness in the monitoring of Pb contamination.

Environmental lead poisoning among children in Porto Alegre state, Southern Brazil

OBJECTIVE

To estimate the prevalence of lead poisoning in children and to identify associated factors, as well as possible local sources of contamination.

METHODS

A cross-sectional prevalence study conducted in 2006 with a random sample of 97 children age zero to five years from a neighborhood in Porto Alegre, Southern Brazil. Blood lead levels were measured and a questionnaire administered to collect information on sociodemographics, recycling and dwelling. A preliminary environmental evaluation was carried out with direct analysis of soil and indirect analysis of air pollution with bioindicators to identify possible sources of contamination. To analyze lead concentrations from the different collection sites, for each type of material studied, ANOVA was performed with a Brown-Forsythe adjustment for heteroscedasticity and with Dunnett's T3 procedure for multiple comparisons of unequal variances.

RESULTS

Blood lead levels > 10.0 µg/dL was found in 16.5% of children. Recycling of waste at home, low father's education level, and increased age of children were associated with increase blood lead levels. High lead levels were found in soil, and there was little indication of lead air pollution.

CONCLUSIONS

A high prevalence of lead poisoning was identified, and the potential sources of contamination in this community appear related to waste recylcing activities. Studies should be conducted with other populations of Brazilian children and evaluate potential sources of local and general contamination, to accurately characterize this issue in Brazil.