Risk Factors For Lead Exposure Research Articles

Evaluation of lead levels in children with chronic constipation

Objectives. This study aimed to assess blood and hair lead levels (BLL and HLL) in children with chronic constipation and compare them to healthy children; and investigated lead exposure’s role in the etiology of constipation. It also explored the correlation between BLL and HLL. Study Design. The study included 84 constipated children aged 3-18 years as the case group and an equal number of constipation-free children as controls. Organic diseases were ruled out through history-taking, physical exams and laboratory tests. Blood and hair samples were collected and analyzed for lead levels using standardized methods. Results. The constipated children group had significantly higher BLL (3.66 µg/dL) compared to the control group (1.61 µg/dL) with no significant HLL difference. Additionally, 48.8% of constipated children exceeded the reference value of 3.5 μg/dL, in contrast to 4.8% of the control group. BLL was unaffected by gender and age, while HLL were higher in girls and low ages. No significant correlation existed between BLL and HLL. The age of the housing showed a positive correlation with higher BLL and HLL. Lead exposure sources like drinking water, home renovation history, parental smoking, or nearby industrial facilities showed no significant relationships with lead levels. Conclusions. Understanding the constipation-lead exposure link is crucial for prevention and intervention. HLL may vary with gender and age due to external lead particles, which is why BLL continues to be a more reliable measure. Healthcare providers should remember to investigate lead exposure risk factors in constipation patients and test BLL when necessary.

Sickle Cell Disease and Lead Poisoning in New York City, 2005-2019.

Previous analyses of New York City (NYC) health department's lead registry indicated that, among children with lead poisoning, an increased prevalence of sickle cell disease (SCD) exists. However, SCD is not considered a risk factor for lead poisoning. We assessed the association between SCD and childhood lead poisoning to determine if specific lead poisoning prevention efforts are needed for children with SCD. We analyzed NYC's lead registry data for children with venous blood lead levels (BLLs) ≥15 mcg/dL during 2005 to 2019. t tests and χ2 tests were performed to compare demographic characteristics, BLLs, and lead exposure risks in non-Hispanic Black children with and without SCD. A t test was used to compare observed SCD prevalence among Black children with BLLs ≥15 mcg/dL with an estimated 0.43% SCD prevalence among Black NYC children. Among 1728 Black children with BLLs ≥15 mcg/dL identified, 37 (2.14%) had SCD. When comparing children with and without SCD, both mean age at peak BLL (62.8 versus 42.7 months; P = .003) and peak BLL (42.59 versus 23.06 mcg/dL; P = .008) were higher for children with SCD. Among risk factors for lead exposure, children with SCD had higher prevalence of pica. Observed SCD prevalence was 1.71% higher than estimated SCD prevalence among Black NYC children (P < .001). We found a potential association between SCD and childhood lead poisoning. Pica emerged as a potentially important risk factor. Our findings might have implications for lead poisoning prevention guidelines for children with SCD.

Impact of the COVID-19 Pandemic on Childhood Lead Testing and Blood Lead Levels

ObjectiveTo evaluate the effect of the COVID-19 pandemic on childhood lead testing and blood lead levels. MethodsA retrospective analysis of lead tests and results was performed across 3 urban medical centers during the pre-COVID-19 (March 10, 2019–March 9, 2020) and COVID-19 (March 10, 2020–March 10, 2022) periods. Interrupted time series analysis with quasi-Poisson regression was used to evaluate changes in lead testing between study periods. The relationship between sociodemographic features with detectable (≧2 µg/dL) and elevated (≧3.5 µg/dL) blood lead levels (BLLs) was assessed with multivariable logistic regression. ResultsAmong a total of 16,364 lead tests across 10,362 patients, weekly testing rates significantly decreased during COVID-19 (relative risk (RR) 0.64, 95% (confidence interval) CI 0.53–0.78). Census tracts with the greatest proportion of pre-1950s housing had a stronger association with detectable BLLs during the COVID-19 period (pre-COVID-19 adjusted odds ratio (aOR) 1.73, 95% CI 1.35–2.20; aOR 2.58, 95% CI 2.13–3.12; interaction P value .014). When limited to 1 year following COVID-19 (March 10, 2020–March 10, 2021), the association between both elevated BLLs (pre-COVID-19: aOR 1.49, 95% CI 0.87–2.53; COVID-19: aOR 3.51, 95% CI 1.98–6.25; interaction P value .032) and detectable BLLs with pre-1950s housing were greater during the COVID-19 period (pre-COVID-19: aOR 1.73, 95% CI 1.35–2.20; COVID-19: aOR 2.56, 95% CI 1.95–3.34; interaction P value .034). ConclusionsThe COVID-19 pandemic led to a significant reduction in lead surveillance and magnified the effect of known risk factors for lead exposure. Concerted clinical, public health, and community advocacy are needed to address care gaps and excess cases of lead poisoning.

Using blood lead concentrations of wildlife sentinels to identify environmental risk factors of lead exposure for public health and wildlife rehabilitation efforts.

Lead poisoning remains a persistent health issue for both humans and wildlife, despite strides to reduce lead contamination in the environment. Using Geographic Information Systems (GIS), this study explores the associations between blood lead levels (BLLs) in wildlife sentinels and possible built environment lead exposure risk factors in the Minneapolis-Saint Paul, Minnesota urban area. Results show a high-level of heterogeneity in animal BLLs (n = 472) across our urban environment and suggest that each kilometer increase in road density is associated with a 17.07% (95% CI: 1.48%, 35.05%) increase in BLL in our study species of Virginia opossums and Eastern gray squirrels, and a 14.28% (95% CI: 1.16%, 29.09%) increase in BLL of rock pigeons. For squirrels and opossums, we see an additional 5.72% (95% CI: 0.59%, 10.85%) increased risk of BLL for every 1000 people per square-mile. The relationship between animal sentinels and environmental hazards can give us an insight into the potential lead exposure risks for humans. The use of wildlife sentinel data to explore environmental risk factors supports a One Health approach to better address public health questions and aid in wildlife rehabilitation related to residual lead poisoning from ambient environmental exposures.

Environmental chemical risk factors of breast cancer in Nigeria III: Metal: Lead

Lead (Pb) is a metalloestrogen and a notable breast cancer risk factor. Lead is an International Agency for Research on Cancer (IARC) group 2A carcinogen. There is no level of exposure to lead that is known to be without harmful effects. Nigeria has literally every known environmental risk factor for lead exposure. Notable sources of lead exposure in Nigeria are lead in contaminated water, paints, artisanal gold ore processing, incineration of lead-containing waste and electronic waste (e-waste). Other sources of lead exposure are ‘tiro’—a lead-laden eye cosmetic, smoked fish particularly those displayed near highways with high vehicular traffic density, vegetables and root crops grown in mining communities, fruit exposed to lead-laden ripening agents, “Calabar chalk”—a lead-laden pica mostly consumed by pregnant women, and children’s toys. Prenatal vitamins supplements, paediatric medication syrups, traditional alcoholic and non-alcoholic drinks such as Kunnu and Zobo were also found as notable sources of lead consumption. Studies in Nigeria on blood lead (Pb) levels in children, pregnant women, and breast milk of nursing women were found to contain high lead levels. Lead exposure is preventable. Hitherto, the neurotoxicity of lead has been the dominant concern as regards lead exposure in children. The breast cancer risk factor now reinforces the zero tolerance for lead exposure.

Is Time Spent Outside the Family Home a Risk Factor for Lead Exposure in Pre-School Children Living in Broken Hill?

Broken Hill is amongst a group of communities internationally that are at greater risk from lead due to active or historical lead industries. Current evidence suggests there is no safe level of lead for young children. This paper describes places outside the family home where young Broken Hill children spend time and considers the potential for this to contribute to lead risk. We interviewed 65 families of children 3 years old or younger and detailed the top five places children spent time at outside the family home. Exposure to private residences outside the family home was recorded for most (88%) young children. Nearly two thirds stayed there five or more hours per week. Most children went there on a weekly basis over many months (median, 12 months), increasing the likelihood of exposure to lead hazards. Further investigation of the lead hazard and risk behaviour of children at these residences would assist in developing guidelines for remediation of the lead hazard for all private residences in Broken Hill. This approach to elucidating the potential sources and pathways of lead and other heavy metal exposures for young children may have merit in other settings where comprehensive zonal remediation is not feasible or may not be warranted.

A new screening index to better target low-level lead exposure in Atlanta, Georgia

Lead poisoning is often seen as a problem of the past. While acute cases are now rare, there is no known safe level of lead for children and blood lead levels at and below 5 μg/dL are associated with neurological deficits. Previous work has established that risk factors for lead exposure include race/ethnicity, poverty, Medicaid enrollment, housing built before 1950, and age. Efficient blood lead screening is crucial in the greater Atlanta area as pockets of poverty and old housing put some children at particularly high risk for chronic exposure to low levels of lead. Here, 20 years of data on children’s blood lead levels in Georgia were used to create maps to assess the spatial distribution of blood lead screening and blood lead levels in the Atlanta area. ZIP code tabulation area (ZCTA)-level screening rates continue to be associated with relative poverty but not with housing age, a well-established risk factor for lead exposure. Building on previous research, a priority screening index based on poverty and housing age was also created to identify specific high-risk census tracts for screening within Atlanta ZCTAs. This index shows a total of 18 highest-priority census tracts in the greater Atlanta area. Together, these 18 tracts contain 2715 children under six years old, 1.7% of all children under six years old in the entire greater Atlanta area.

Blood Lead Levels of Children Using Traditional Indian Medicine and Cosmetics: A Feasibility Study.

BackgroundTraditional 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.MethodsWe 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.ResultsThe 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).ConclusionsIt 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.

Lead exposure from households and school settings: influence of diet on blood lead levels.

Lead is known as a potent toxicant to human health, particularly for children while their central nervous system is developing. The aim of this study was to investigate the associations between blood lead levels (BLLs) and lead exposure in the children's diet, home, and school environments. A cross-sectional study was conducted with 153 children aged 1-4years, in four day care centers (DCCs), where a high prevalence of lead exposure was previously found. Lead determination by graphite furnace atomic absorption spectrometry (GF-AAS) was performed for venous blood, drinking water collected in the DCCs, and the 24-h diet (n = 64). Environmental screenings were conducted to evaluate lead concentrations in the tableware, buildings, and playground items in all DCCs and children's homes (n = 18) by using a field-portable X-ray fluorescence analyzer (FP-XRF). The BLL mean was 2.71μgdL-1. Means for 24-h lead concentrations in the diet were 1.61 and 2.24μgkg-1 of body weight (BW) in two DCCs. Lead concentrations in the water supply were lower than 2μgL-1. More than 11% of the DCCs' environmental analyses presented lead concentrations higher than or equal to 1mgcm-2, as defined by the USEPA. The diet was not found to be a risk factor for lead exposure, but households and DCC settings raised concern. Children's exposure to lead in DCC environments, where they spend the most part of their weekdays, appeared to be relevant. Graphical abstract ᅟ.

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.

Prenatal exposure to lead in France: Cord-blood levels and associated factors: Results from the perinatal component of the French Longitudinal Study since Childhood (Elfe).

As a result of the ban on lead in gasoline on 2nd January 2000, the French population's exposure to lead has decreased in recent years. However, because of the acknowledged harmful cognitive effects of lead even at low levels, lead exposure remains a major public health issue. In France, few biomonitoring data are available for exposure to lead in pregnant women and newborn. The purpose of the perinatal component of the French human biomonitoring (HBM) program was to describe levels of various biomarkers of exposure to several environmental pollutants, including lead, among mother-baby pairs. In this paper, we aimed to describe the distribution of cord blood lead levels (CBLL) in French mother-baby pairs, and to estimate the contribution of the main lead exposure risk factors to these levels. A total of 1968 mother-baby pairs selected from the participants of the perinatal component of the French HBM program were included in the study on lead. Lead levels were analyzed in cord blood collected at child delivery by inductively coupled plasma-mass spectrometry (ICP-MS). The data collected included biological sample, socio-demographic characteristics, environmental and occupational exposure, and information on dietary factors. CBLL were quantified for 99.5% of the sample. The CBLL geometric mean was 8.30 μg/l (95% CI [7.94-8.68]) with a 95th percentile of 24.3 μg/l (95% CI [20.7-27.1]). Factors significantly associated with CBLL were tap water consumption, alcohol consumption, shellfish consumption, vegetable consumption, bread consumption, smoking, and the mother being born in countries where lead is often used. This study provides the first reference value for CBLL in a random sample of mother-baby pairs not particularly exposed to high levels of lead (24.3 μg/l). A substantial decrease in CBLL over time was observed, which confirms the decrease of exposure to lead among the general population. CBLL observed in this French study were in the range of those found in recent surveys conducted in other countries.

Blood Lead Levels and Risk Factors for Lead Exposure in a Pediatric Population in Ho Chi Minh City, Vietnam.

Although lead recycling activities are a known risk factor for elevated blood levels in South East Asia, little is known regarding the prevalence of and risk factors for elevated blood lead levels (BLL) among the general pediatric population in Vietnam. This study is a cross-sectional evaluation of 311 children from Children’s Hospital #2 in Ho Chi Minh City, Vietnam. Capillary blood lead testing was performed using the LeadCare II. Mean BLLs were 4.97 μg/dL (Standard Deviation (SD) 5.50), with 7% of the participants having levels greater than 10 μg/dL. Living in Bing Duong province (OR 2.7, 95% CI 1.4–5.6.1) or the Dong Nai province (OR 2.3, 95% CI 1.0–5.1) and having an age greater than 12 months (OR 6.0, 95% CI 3.1–11.8) were associated with higher BLLs. The prevalence of elevated BLLs in Vietnam is consistent with other SE Asian countries. Mean BLLs in Ho Chi Minh City are markedly less than those seen in a separate study of children living near lead recycling activities. Additional evaluation is necessary to better detail potential risk factors if screening is to be implemented within Vietnam.

Blood lead levels and risk factors for lead exposure among pregnant women in western French Guiana: the role of manioc consumption

ABSTRACTConcerns regarding lead (Pb) poisoning in French Guiana first arose in 2011 following the discovery of excessively high levels of the metal amongst children in a small neighborhood without any apparent source of Pb. Since 2012, blood lead level (BLL) measurement has been proposed for all pregnant women in western French Guiana. The aim of this study was to determine BLL in pregnant women in this region and identify factors associated with elevated BLL. An observational study of a consecutive sample of women who delivered in the maternity ward of the hospital was conducted. Risk factors were investigated using a questionnaire administered postdelivery by midwives (N = 531). Approximately 25 and 5% of women displayed BLL of ≥50 μg/L and ≥100 µg/L, respectively. The geometric mean was 32.6 μg/L. Factors that were significantly associated with an elevated BLL after modeling (multivariate linear regression) included place of residence along the Maroni river, low level of education, daily consumption of manioc derivatives, weekly and daily consumption or personal preparation of manioc flour during pregnancy, and weekly consumption of wild game. This study provides insight into the regional and social disparities in BLL in French Guiana and potential sources of exposure. Evidence indicates that foods that are primarily produced and consumed in the Guiana Shield significantly affect BLL levels. Taken together with existing data, our results demonstrate that specific actions in terms of prevention, screening, and care are required to be adapted and put into place in order to reduce exposure.

Blood lead levels in children aged between 1 and 6 years old in La Plata, Argentina. Identification of risk factors for lead exposure.

Lead has neurotoxic effects in children, even at a very low level in blood. The risk factors (RFs) for lead exposure have not been adequately identified in La Plata. The objectives of this study were to determine mean blood lead levels and identify RFs in children aged 1 to 6 years old living in La Plata and the outskirts. A cross-sectional study was conducted in children who attended primary health care centers for a health check-up. Blood lead levels were determined by atomic absorption spectroscopy, and a socioenvironmental survey was administered to outline RFs. The Mann-Whitney test was used to compare measurements. A multivariate statistical analysis was done to establish the most relevant RFs. A total of 319 children participated (51% were boys); the median (interquartile range) blood lead level was 2.2 pg/dL (1.1-3.6 pg/dL). Significant mean differences in blood lead levels were observed for age≤ 3years old, anemia, pica behavior, overcrowding, dirt floors, and maternal education < 7 years. Age≤ 3years old and pica behavior were both RFs with significant odds ratios (ORs). The OR as adjusted by logistic regression was significant only for age≤ 3years old. The median blood lead level in the studied population was 2.2 pg/dL. The main RFs identified for lead exposure were age≤ 3years old and pica behavior. Other less relevant RFs included anemia, maternal education < 7 years, overcrowding, and dirt floors.

The blood lead levels of outpatients aged 1–18 years from Lu’an, China, 2012–2014

To evaluate blood lead levels (BLLs) and possible influencing factors among children and adolescents in Lu’an, we collected blood samples of 3266 outpatients aged 1–18 years from January 2012 to December 2014 and BLLs were determined by atomizer absorption spectrophotometer. The results showed that the geometric mean (GM) of BLLs was 29.53μg/L (95% CI: 29.00–30.06μg/L) and the prevalence of BLLs ≥50 and 100μg/L were 17.7% and 0.2%, respectively. The GM BLLs and prevalence of BLLs ≥50μg/L were increased with age before 7 years old and then slightly decreased, and, contrary to previous studies, they were the highest at Jan–Feb and the lowest at Sep–Oct. From 2012 to 2014, the GM BLLs were significantly increased (P<0.001) while the prevalence of BLLs ≥50μg/L was decreased but with no significant difference (P>0.05). These results suggested that although the BLLs of Lu’an children were lower than most areas of China and several neighboring cities as previously reported, they were still higher than that of developed countries. Meanwhile, the GM BLLs of children and adolescents from Lu’an have a trend of increase in recent years. A lot of future works need to be done to identify the risk factors for lead exposure.

Risk Factors for Lead Exposure in Adult Population in Southern Brazil

In Brazil there is no systematic evaluation to access blood lead levels (BLL) in the general population and few studies with adults have been published. The aim of this study was to examine the socioeconomic, environmental, and lifestyle determinants of BLL in the adult Brazilian population. In total, 959 adults, aged 40 years or more, were randomly selected in a city in southern Brazil. Information on socioeconomic, dietary, lifestyle, and occupational background was obtained by interviews. A spatial analysis was conducted to discern whether there were any identifiable sources of exposure. BLL were measured by inductively coupled plasma–mass spectrometry. There was an adjustment for gender, age, race, education, income class, smoking status, alcohol consumption, occupation, and red meat or cow milk consumption (Model 1), and for occupation and gender (Model 2). The geometric mean of BLL was 1.97 μg/dl (95% CI: 1.9–2.04 μg/dl). In Model 1, BLL were positively associated with male gender, older age, and drinking and smoking habits, and less frequently with milk consumption. In Model 2, data showed higher BLL in non-white than white participants, in former smokers and individuals with current or former employment in lead (Pb) industries. The participants living in the area with more Pb industries had higher BLL (3.3 μg/dl) compared with those residing in other areas with no or fewer Pb industries (1.95 μg/dl). Despite the low BLL found in adults living in an urban area, Pb industries need to be monitored and regulatory laws implemented to prevent metal contamination in urban settings.

Risk Factors for Lead Exposure in Adult Population in Southern Brazil

Risk Factors for Lead Exposure in Adult Population in Southern Brazil

Spatiotemporal patterns and risk factors for lead exposure in endangered California condors during 15 years of reintroduction.

Large-scale poisoning events are common to scavenging bird species that forage communally, many of which are in decline. To reduce the threat of poisoning and compensate for other persistent threats, management, including supplemental feeding, is ongoing for many reintroduced and endangered vulture populations. Through a longitudinal study of lead exposure in California condors (Gymnogyps californianus), we illustrate the conservation challenges inherent in reintroduction of an endangered species to the wild when pervasive threats have not been eliminated. We evaluated population-wide patterns in blood lead levels from 1997 to 2011 and assessed a broad range of putative demographic, behavioral, and environmental risk factors for elevated lead exposure among reintroduced California condors in California (United States). We also assessed the effectiveness of lead ammunition regulations within the condor's range in California by comparing condor blood lead levels before and after implementation of the regulations. Lead exposure was a pervasive threat to California condors despite recent regulations limiting lead ammunition use. In addition, condor lead levels significantly increased as age and independence from intensive management increased, including increasing time spent away from managed release sites, and decreasing reliance on food provisions. Greater independence among an increasing number of reintroduced condors has therefore elevated the population's risk of lead exposure and limited the effectiveness of lead reduction efforts to date. Our findings highlight the challenges of restoring endangered vulture populations as they mature and become less reliant on management actions necessary to compensate for persistent threats.

Lead exposure in young school children in South African subsistence fishing communities

BackgroundLead is an established toxic substance, with wide-ranging health effects, including neurodevelopmental decrements and behavioural problems, even at low levels in blood. Anecdotal reports of lead melting to make fishing sinkers in South African subsistence fishing communities prompted the conduct of an epidemiological study in two South African fishing villages to investigate the extent of lead melting and the associated risks in children. ObjectivesThe objectives of the study were to determine the extent of lead melting, and the blood lead distributions and associated risk factors in children. MethodsCross-sectional, analytical studies were undertaken among 160 young school children in the fishing villages of Struis Bay and Elands Bay located along the south-eastern and western South African coastline, respectively. Blood samples were collected for lead content analysis, and anthropometric and hemoglobin measurements were taken. Questionnaires were administered to obtain information about socio-economic status and risk factors for lead exposure. ResultsBlood lead levels ranged from 2.2 to 22.4µg/dl, with the mean blood lead level equalling 7.4. Around 74% of the children had blood lead levels ≥5µg/dl and 16% had blood lead levels ≥10µg/dl. Socio-economic factors, and lead melting practices were strongly associated with elevated blood lead levels. ConclusionsBlood lead levels in these remote subsistence fishing communities were unexpectedly elevated, given the absence of local lead industries or other obvious sources of lead exposure. Lead exposure and poisoning is an important, yet neglected, public health concern in South African subsistence fishing communities, and potentially on the entire African continent.

Blood lead levels among children aged 0 to 6 years in 16 cities of China, 2004-2008

Background The adverse health effects of lead for children under 6 years are well known. Studies to assess the lead exposure among children in China are small in sample size and lack of national representative data. The aim of this study therefore was to describe blood lead levels and identify risk factors for lead exposure among children aged 0 to 6 years living in 16 cities in China. Methods We analyzed data from blood lead levels surveillance in China carried out in 16 large cities between 2004 and 2008. A stratified clustered random sampling strategy was used. A total of 69 968 children aged 0 to 6 years were included. We conducted multiple Logistic regression analyses to explore risk factors to high blood lead level. Results The geometric mean blood lead level of the children was 4.50 μg/dl (median: 4.90 μg/dl; IQR: 3.20-7.00 μg/dl). Overall prevalence of blood lead level ≥10.00 μg/dl among 0- to 6-year-old children was 7.57%. But the proportion of blood lead level ≥5.00 but &lt;10.00 μg/dl was 42.12%. Blood lead levels were significantly higher in boys (4.63 μg/dl) than in girls (4.35 μg/dl) (P &lt;0.0001). The geometric mean blood lead levels and prevalence of blood lead level ≥10.00 μg/dl increased with age (P &lt;0.0001 for the two trends). After controlling for sociodemographic, dietary and behavior factors, multivariable analysis indicated that lower maternal education, male gender, younger age, often biting pencil or/and toys, walking or playing for long time on the street, not washing hands before eating are major risk factors for higher lead levels. Conclusions The blood lead levels among Chinese children in urban areas are lower than previous studies but close to those of developed countries. However, children with low lead exposure account for almost half and the sociodemographic factors (age, male sex, and low mother education level) continue to be associated with higher blood lead levels.