Blood lead levels and associated factors among children in Guiyu of China: a population-based study.
ABSTRACT: Children's health problems caused by the electronic waste (e-waste) lead exposure in China remains. To assess children's blood lead levels (BLLs) in Guiyu of China and investigate risk factors of children's elevated BLLs in Guiyu.842 children under 11 years of age from Guiyu and Haojiang were enrolled in this population-based study during 2011-2013. Participants completed a lifestyle and residential environment questionnaire and their physical growth indices were measured, and blood samples taken. Blood samples were tested to assess BLLs. Children's BLLs between the two groups were compared and factors associated with elevated BLLs among Guiyu children were analyzed by group Lasso logistic regression model.Children living in Guiyu had significant higher BLLs (7.06 µg/dL) than the quantity (5.89 µg/dL) of Haojiang children (P<0.05). Subgroup analyses of BLLs exceeding 10 µg/dL showed the proportion (24.80%) of high-level BLLs for Guiyu children was greater than that (12.84%) in Haojiang (P<0.05). Boys had greater BLLs than girls, irrespectively of areas (P<0.05). The number of e-waste piles or recycling workshops around the house (odds ratio, 2.28; 95% confidence interval [CI], 1.37 to 3.87) significantly contributed to the elevated BLLs of children in Guiyu, and girls had less risk (odds ratio, 0.51; 95% CI, 0.31 to 0.83) of e-waste lead exposure than boys.This analysis reinforces the importance of shifting e-waste recycling piles or workshops to non-populated areas as part of a comprehensive response to e-waste lead exposure control in Guiyu. To correct the problem of lead poisoning in children in Guiyu should be a long-term mission.
Project description:To investigate the attention-deficit/hyperactivity disorder (ADHD) status among preschool-aged children in Guiyu, an electronic waste (e-waste) recycling town in Guangdong, China.Two hundred and forty-three parents were surveyed regarding ADHD behaviors in their children (aged 3-7 years) based solely on the DSM-IV criteria. The peripheral blood samples were taken from these children to measure blood lead levels (BLLs) and blood cadmium levels (BCLs).12.8% of children met the criteria for ADHD, of which the inattentive, hyperactive/impulsive and combined subtypes were 4.5%, 5.3% and 2.9% respectively. Of all children, 28.0% had BLLs???10 ug/dL and only 1.2% had BCLs???2 ug/L, levels conventionally considered high. Either modeled by univariate or multivariable analysis, the three ADHD scores (inattentive, hyperactive/impulsive and total scores) calculated from the Parent Rating Scale showed strong positive correlations with BLLs but not with BCLs. Furthermore, children with high BLLs had 2.4 times higher risk of ADHD than those with low BLLs (OR: 2.4 [95% CI: 1.1-5.2]). When each of the 18 categories on the Parent Rating Scale was separately analyzed, children with high BLLs had significant higher risks for positive ADHD symptoms than those with low BLLs in 12 of the 18 categories (ORs ranged from 2.1 [95% CI: 1.1-3.9] to 3.6 [95% CI: 1.7-7.5]).This study suggests that environmental lead contamination due to e-waste recycling has an impact on neurobehavioral development of preschool children in Guiyu.
Project description:Informal electronic waste (e-waste) recycling results in serious environmental pollution of polybrominated diphenyl ethers (PBDEs) and heavy metals. This study explored whether there is an association between PBDEs, heavy metal and key growth- and development-related hormones in children from Guiyu, an e-waste area in southern China. We quantified eight PBDE congeners using gas chromatographic mass spectrometry, lead and cadmium utilizing graphite furnace atomic absorption spectrometry, three thyroids with radioimmunoassay and two types of growth hormones by an enzyme-linked immune-sorbent assay (ELISA) in 162 children, 4 to 6 years old, from Guiyu. In blood, median total PBDE was 189.99 ng/g lipid. Lead and cadmium concentrations in blood averaged 14.53±4.85 µg dL-1 and 0.77±0.35 µg L-1, respectively. Spearman partial correlation analysis illustrated that lead was positively correlated with BDE153 and BDE183. Thyroid-stimulating hormone (TSH) was positively correlated with almost all PBDE congeners and negatively correlated with insulin-like growth factor binding protein-3 (IGFBP-3), whereas free triiodothyronine (FT3) and free thyroxine (FT4) were negatively correlated with BDE154. However, no correlation between the hormones and blood lead or cadmium levels was found in this study. Adjusted multiple linear regression analysis showed that total PBDEs was negatively associated with FT3 and positively associated with TSH. Notably, FT4 was positively correlated with FT3, house functions as a workshop, and father's work involved in e-waste recycling and negatively correlated with vitamin consumptions. TSH was negatively related with FT4, paternal residence time in Guiyu, working hours of mother, and child bean products intake. IGFBP-3 was positively correlated with IGF-1 and house close to an e-waste dump. These results suggest that elevated PBDEs and heavy metals related to e-waste in Guiyu may be important risk factors for hormone alterations in children.
Project description:Electronic waste (e-waste) is the fastest growing solid waste stream worldwide and mostly ends up in developing countries where residents use primitive methods for recycling. The most infamous e-waste recycling town, Guiyu in Southeast China, has been recycling since the mid-1990s. E-waste contains several harmful chemicals, including lead (Pb), cadmium (Cd), chromium (Cr), and manganese (Mn). In 2011-12, the e-waste Recycling Exposures and Community Health (e-REACH) Study enrolled 634 pregnant women living in Guiyu and Haojiang, a control site, both in Shantou, China. The women completed a questionnaire and gave maternal blood, cord blood, and maternal urine, which were analyzed for Pb, Cd, Cr, and Mn. Maternal blood Pb, Cd, and Cr concentrations were significantly higher in Guiyu compared to Haojiang. In Guiyu, the geometric mean of Pb concentration in maternal blood was 6.66?µg/dL (range: 1.87-27.09?µg/dL) and was 1.74-fold greater than in Haojiang (95% CI: 1.60, 1.89). In cord blood, Pb concentration was 1.53-fold higher in Guiyu (95% CI: 1.38, 1.68). In maternal urine, Cd (ratio: 2.15, 95% CI: 1.72, 2.69) and Mn (ratio: 2.60, 95% CI: 2.04, 3.31) concentrations were significantly higher in Guiyu in comparison to Haojiang. In conclusion, pregnant women in Guiyu were at risk for increased exposure to heavy metals.
Project description:Background:Traditional Indian cosmetics and Ayurvedic medicines may contain lead. Previous studies have shown a relationship between eye cosmetic use (kohl) in children and elevated blood lead levels (BLLs)?>?10?µg/dL. However, an association between Ayurvedic use and elevated BLLs in children is unknown and understudied. Methods:We assessed the feasibility of collecting BLLs in children attending Ayurvedic outpatient settings in India. Our pilot study took place over 3 days in the summer of 2010 at a large public Ayurveda hospital and a small pediatric clinic in southern India. Using a trained interpreter, we administered a standardized questionnaire in Malayalam, assessing sociodemographics, Ayurvedic medicine use, kohl use, and other potential risk factors for lead exposure, to parents of pediatric outpatients. We also analyzed BLLs using a portable lead analyzer. Results:The study enrolled 29 children (mean age, 3.8?years). The mean BLL was 6.7?µg/dL (SD?=?3.5; range, 3.5-20.2). Seventy-two percent of the children used Ayurvedic medicine in the past 2 years and 55% reported kohl use. Mean BLL of Ayurvedic users and nonusers was 6.2?µg/dL and 8.5?µg/dL, respectively (P?=?.08). Kohl users had a statistically significant higher BLL than nonusers (8.0?µg/dL vs 5.3?µg/dL, P?=?.03). Conclusions:It is feasible to collect BLLs in pediatric Ayurvedic outpatient clinics in southern India. Collaborative relationships with community members and hospital staff were essential. Further research is needed to investigate Ayurveda and kohl use as risk factors for elevated lead burden among Indian children.
Project description:Despite the removal of lead from gasoline in 1997, elevated blood lead levels (BLLs) > 5 µg/dL are still detectable in children living in Mexico City. The use of lead-glazed ceramics may explain these persistent exposure levels. Mexico lacks a national surveillance program for BLL, but temporal trends can be derived from epidemiological studies. With this approach, we leveraged a series of birth cohorts to report BLL trends from 1987 to 2002 and expanded our analysis to 2015. Data were from 1?5-year-old children from five Mexico City cohorts followed between 1988 and 2015. BLLs are reported on 1963 children, who contributed 4975 BLLs. We estimated the trend of mean BLL, which decreased from 15.7 µg/dL in 1988, to 7.8 µg/dL in 1998 (a year after the total ban of lead in gasoline), to 1.96 µg/dL in 2015. The proportion of BLL ? 5 µg/dL decreased from 92% (1988?1998) to 8% (2008?2015). The use of lead-glazed ceramics was associated with an 11% increase in BLLs throughout the study period. Replacing lead-based glazes in traditional ceramics may be the key to further reducing exposure, but this presents challenges, as it involves a cultural tradition deeply rooted in Mexico. In addition, the creation of a rigorous, standardized, and on-going surveillance program of BLL is necessary for identifying vulnerable populations.
Project description:Background:Local, state, and national childhood blood lead surveillance is based on healthcare providers and clinical laboratories reporting test results to public health departments. Increased interest in detecting blood lead level (BLL) patterns and changes of potential public health significance in a timely manner has highlighted the need for surveillance systems to rapidly detect and investigate these events. Objective:Decrease the time to detect changes in surveillance patterns by using an alerting algorithm developed and assessed through historical child blood lead surveillance data analysis. Methods:We applied geographic and temporal data-aggregation strategies on childhood blood lead surveillance data and developed a novel alerting algorithm. The alerting algorithm employed a modified cumulative summary/Shewhart algorithm, initially applied on 113 months of data from two jurisdictions with a known increase in the proportion of children <6 years of age with BLLs =>5 µg/dl. Results:Alert signals retrospectively identified time periods in two jurisdictions where a known change in the proportion of children <6 years of age with BLLs >=5 µg/dl occurred. Additionally, we identified alert signals among six of the 18 (33%) randomly selected counties assessed where no previously known or suspected pattern changes existed. Conclusion:The modified cumulative summary/Shewhart algorithm provides a framework for enhanced blood lead surveillance by identifying changes in the proportion of children with BLLs >=5 µg/dl. The algorithm has the potential to alert public health officials to changes requiring further important public health investigation.
Project description:CONTEXT:Several cross-sectional studies have assessed the association of lead exposure with type 2 diabetes and cardiometabolic risk factors in adults; however, studies of such associations in childhood are rare. OBJECTIVE:We assessed the prospective associations of prenatal exposure to lead with type 2 diabetes and cardiometabolic risk factors in children. DESIGN:The Early Life Exposure in Mexico to Environmental Toxicants is a birth cohort study of pregnant women and their offspring. SETTING:Public hospitals in Mexico City. PATIENTS OR OTHER PARTICIPANTS:Women were recruited during pregnancy; their offspring were recruited for a follow-up visit at age 10 to 18 years (n = 369). MAIN OUTCOME MEASURES:We measured fasting serum markers of type 2 diabetes and cardiometabolic risk factors in children, including fasting glucose, insulin, and lipids. The index of insulin resistance was calculated. RESULTS:The geometric mean of maternal blood lead levels (BLLs) during pregnancy was 4.3 µg/dL (95% confidence interval [CI]): 4.0-4.6 µg/dL) in the entire sample. In boys, those with maternal BLLs ? 5 µg/dL (compared with those with BLLs < 5 µg/dL) had significantly lower z scores for total cholesterol (? = -0.41, 95% CI: -0.71, -0.12), high-density lipoprotein cholesterol (? = -0.32, 95% CI: -0.59, -0.05), and low-density lipoprotein cholesterol (? = -0.52, 95% CI: -0.81, -0.22), adjusting for covariates. No associations were detected in girls. CONCLUSIONS:In our study, we found that higher prenatal exposure to lead was associated with lower levels of cholesterol in children following a sex-specific pattern. Further studies with a larger sample size that examine whether sex is a potential modifier are needed to confirm our findings.
Project description:Children's blood lead concentrations have been closely monitored over the last two decades in the United States. The bio-monitoring surveillance data collected in local agencies reflected the local temporal trends of children's blood lead levels (BLLs). However, the analysis and modeling of the long-term time series of BLLs have rarely been reported. We attempted to quantify the long-term trends of children's BLLs in the city of Syracuse, New York and evaluate the impacts of local lead poisoning prevention programs and Lead Hazard Control Program on reducing the children's BLLs. We applied interrupted time series analysis on the monthly time series of BLLs surveillance data and used ARMA (autoregressive and moving average) models to measure the average children's blood lead level shift and detect the seasonal pattern change. Our results showed that there were three intervention stages over the past 20 years to reduce children's BLLs in the city of Syracuse, NY. The average of children's BLLs was significantly decreased after the interventions, declining from 8.77?g/dL to 3.94?g/dL during1992 to 2011. The seasonal variation diminished over the past decade, but more short term influences were in the variation. The lead hazard control treatment intervention proved effective in reducing the children's blood lead levels in Syracuse, NY. Also, the reduction of the seasonal variation of children's BLLs reflected the impacts of the local lead-based paint mitigation program. The replacement of window and door was the major cost of lead house abatement. However, soil lead was not considered a major source of lead hazard in our analysis.
Project description:Lead exposure is associated with poor cognitive development in children. Very few studies in sub-Saharan Africa (SSA) have studied blood lead levels (BLLs) and non-gasoline sources of exposure in children. Data from a birth cohort in Benin (2011-2013) suggested that 58% of 1-year-old children had BLLs > 50 ug/L. We aimed to investigate the prevalence of elevated BLLs (>50 µg/L and >100 µg /L) among 425 of these children at 6 years of age in 2016-2018 and to compare BLLs between age 1 and 6 years, and study sources of lead at age 6 years. BLLs were analysed by inductively coupled plasma mass spectrometry. Multiple linear regression and quantile regressions were used to study potential sources of lead. The prevalence of BLLs > 50 µg/L in children was 59.5% (Geometric Mean (GM) 56.4 µg/L, 95% CI: 54.1-58.7) at 6 years of age compared to 54.8% (GM 56.5 µg/L, 95% CI: 53.4-59.6) at 1 year of age. The prevalence of children with BLLs > 100 µg/L decreased from 14.4% at 1 year of age to 8.2% at 6 years of age. After adjustment for all other covariates, consumption of peanuts more than once per month was significantly associated with a 22.0% (95% CI: 4.6, 42.5) increment in BLLs at age 6 years compared with no consumption. Consumption of bushmeat killed by lead bullets at age 6 years was associated with an increase in the higher percentiles of BLLs (P75) compared with the absence of this source. Other potential sources of lead associated with BLLs with marginal significance were consumption of rice, paternal occupational exposure, and the presence of activity with the potential use of lead. This prospective cohort confirms the persistently high prevalence of elevated BLLs in children residing in a rural region in the south of Benin, as well as the presence of multiple and continuous sources of lead. These results highlight the need for prevention programs to reduce and eliminate lead exposure in children.
Project description:There is no safe detectable level of lead (Pb) in the blood of young children. In the United States, predominantly African-American Black children are exposed to more Pb and present with the highest mean blood lead levels (BLLs). However, racial disparity has not been fully examined within risk factors for early childhood Pb exposure. Therefore, we conducted secondary analysis of blood Pb determinations for 2841 US children at ages 1-5 years with citizenship examined by the cross-sectional 1999 to 2010 National Health and Nutrition Examination Survey (NHANES). The primary measures were racial disparities for continuous BLLs or an elevated BLL (EBLL) ?5 µg/dL in selected risk factors between non-Hispanic Black children (n = 608) and both non-Hispanic White (n = 1208) or Hispanic (n = 1025) children. Selected risk factors included indoor household smoking, low income or poverty, older housing built before 1978 or 1950, low primary guardian education <12th grade/general education diploma (GED), or younger age between 1 and 3 years. Data were analyzed using a regression model corrected for risk factors and other confounding variables. Overall, Black children had an adjusted +0.83 µg/dL blood Pb (95% CI 0.65 to 1.00, p < 0.001) and a 2.8 times higher odds of having an EBLL ?5 µg/dL (95% CI 1.9 to 3.9, p < 0.001). When stratified by risk factor group, Black children had an adjusted 0.73 to 1.41 µg/dL more blood Pb (p < 0.001 respectively) and a 1.8 to 5.6 times higher odds of having an EBLL ?5 µg/dL (p ? 0.05 respectively) for every selected risk factor that was tested. For Black children nationwide, one in four residing in pre-1950 housing and one in six living in poverty presented with an EBLL ?5 µg/dL. In conclusion, significant nationwide racial disparity in blood Pb outcomes persist for predominantly African-American Black children even after correcting for risk factors and other variables. This racial disparity further persists within housing, socio-economic, and age-related risk factors of blood Pb outcomes that are much more severe for Black children.