Sources and risk factors for lead exposure in indigenous children of the Peruvian Amazon, disentangling connections with oil activity.

INTRODUCTION: In the Corrientes river basin, Peruvian Amazon, lead exposure among indigenous communities was first reported in 2006. To address controversy regarding the main source of exposure, this study aimed to identify the sources and risk factors for lead exposure among children from the communities in question, and to clarify the potential relationship with oil activity. METHODS: This cross-sectional study was conducted in six communities. Participants were children aged 0-17 years and their mothers. Data collection included blood lead levels (BLLs) and hemoglobin determination, a questionnaire on risk factors and environmental sampling. We used age-stratified multivariate regression models, with generalized estimating equation to account for correlation within households. RESULTS: Twenty-seven percent of the children had BLLs ≥10 µg/dl. Mother's BLLs ≥10 µg/dl, playing and chewing lead scraps, fishing ≥three times/week, and living in highly oil-exposed communities increased the risk of having BLLs ≥10 µg/dl. Lead concentrations in sediment, soil, dust, and fish samples were below reference values. CONCLUSIONS: Mother's BLLs ≥10 µg/dl, playing and chewing lead scraps to manufacture fishing sinkers were the most important risk factors for children's BLLs ≥10 µg/dl. The connection with oil activity appears to be through access to metal lead from the industry's wastes.

Binational study of pediatric blood lead levels along the United States/Mexico border.

To evaluate lead exposure among children living in border communities, the states of Arizona and New Mexico in the United States (US), and the states of Sonora and Chihuahua in Mexico collaboratively requested that the Centers for Disease Control and Prevention (CDC) provide technical assistance to document pediatric blood lead levels (BLLs) in children living along this part of the US/Mexico border. Two studies were conducted to evaluate BLLs of children aged 1-6 years. In 1998, 1210 children were tested in the Arizona/Sonora study; in 1999, 874 children were tested in New Mexico/Chihuahua. Overall geometric mean BLL was 32.5 microg/l (95% Confidence Interval 31.5-33.5) with BLLs ranging from below limit of detection to 320.0 microg/l. Mean BLLs were higher among children living on the Mexican side of the border (43.2 microg/l) compared to those on the US side (22.3 microg/l). Mean BLLs ranged from 14.9 to 31.2 microg/l at the US sites and from 26.9 to 55.2 microg/l at the Mexican sites. This study used a convenience sample and cannot be considered representative of the general population. Nonetheless, the range of mean BLLs among the sites and especially the higher mean BLLs among children living in the border communities in Mexico suggests different exposures to lead and warrants further attention.

Risk factors for lead poisoning among Cuban refugee children.

OBJECTIVES: This study was designed to explore whether parental activities such as repairing cars, welding, and rebuilding car batteries are risk factors for lead poisoning among Cuban refugee children in Miami-Dade County. METHODS: The authors performed a cross-sectional study of 479 children aged 12-83 months who had lived in Cuba during the six months prior to immigrating to the U.S. Lead levels were obtained, and parents provided information on demographics, home/neighborhood environment in Cuba prior to immigration, family/occupational factors prior to immigration, and child behavior factors. RESULTS: Of 479 children, 30 (6.3%) had elevated blood lead levels (EBLLs), defined as > or = 10 microg/dL, based on the Centers for Disease Control and Prevention action level. In multivariate analysis, racial/ethnic identification other than white, living in a home built after 1979, car repair in the home or yard, eating paint chips, and male sex were independently associated with EBLL. CONCLUSIONS: Risk factors for lead poisoning among immigrant children may differ from those among U.S.-born children. Screening of immigrant children who may have been exposed in their country of origin and education of immigrant parents about lead exposure hazards associated with activities such as car repair should be considered in the design of lead poisoning prevention and control programs.

Environmental lead exposure during early childhood.

OBJECTIVE: To determine the relative contribution of residential lead hazards to children's blood lead concentrations during early childhood. METHODS: We enrolled children 6 months of age and followed them until 24 months of age. Blood and samples of dust, soil, water and paint were analyzed for lead at 6-month intervals, and interviews were conducted to estimate nutritional, behavioral, and demographic factors linked with lead exposure. RESULTS: Of the 276 children enrolled, 249 (90%) were followed until 24 months of age. The geometric mean blood lead concentration of children at 6 months of age was 2.9 microg/dL (95% CI, 2.7-3.1). At 24 months of age, children's mean blood lead was 7.5 microg/dL; 82 (33%) had a blood lead level of > or = 10 microg/dL. In adjusted analyses, lead-contaminated floor dust, soil, and water contributed to children's lead intake throughout the first 2 years of life (P < .05). Lead-contaminated dust from window troughs was a source of lead exposure, especially in the second year of life. Dietary iron intake, but not calcium intake, was inversely associated with blood lead levels (P < .05). Blood lead concentration was over 50% higher in black than in white children (P = .0001). CONCLUSION: Lead-contaminated house dust is the major source of lead intake during early childhood. Black children remain at increased risk for higher blood lead concentration after adjusting for environmental lead exposures and dietary intake.

Implications of tooth root hypercementosis in a Barbados slave skeletal collection.

A 17th- to 19th-century cemetery sample of 104 slaves from Newton Plantation (Barbados) shows uniquely high hypercementosis prevalence, as well as unexpectedly high and variable skeletal lead content. A variety of biological and archeological factors indicates that individuals with lower amounts of these anomalies (relative to age at death) were probably African-born, first-generation slaves. The hypercementosis is related to the progression of periodontal disease as assessed from alveolar bone. Although the hypercementosis is endemic in the Caribbean black population, it does not as yet have a clear explanation. We suggest the etiology might relate to chronic malnutrition involving periodic, seasonal rehabilitation.