Blood lead levels of children and its trend in China

Trace metals and magnetic particles in PM2.5: Magnetic identification and its implications

Magnetic measurement was combined with geochemical analysis to investigate the trace metal pollution of PM_2.5. The study was carried out in Nanjing, China, where the average PM_2.5 concentrations in summer and winter in 2013–2014 were 66.37 and 96.92 μg/m³, respectively. The dominant magnetic mineral in PM_2.5 had a low-coercivity pseudo-single domain and consisted of magnetite and hematite. Iron-oxide magnetic particles comprised spherical as well as angular particles. Stable Pb isotopic ratio determinations showed that Pb in summer samples derived from coal emissions while the main sources of winter samples were smelting industry and coal emissions. The magnetic properties of the particles correlated strongly with trace metals derived from anthropogenic activities, such as industrial emission, coal combustion, and traffic vehicle activities, but poorly with those derived from natural sources. In the multiple linear regression analysis, Cr and Fe had higher correlation coefficients (training R > 0.7) in contrast to the low training R of As, Cd, Ni, Sr, and Ti (<0.5) determined using the PM_2.5 concentrations and magnetic parameter values as the decision variables. Our results support the use of environmental magnetism determinations as a simple and fast method to assess trace metals in urban particulate matter.

Generation of domestic waste electrical and electronic equipment on Fernando de Noronha Island: qualitative and quantitative aspects

The accelerated growth trajectory of waste electrical and electronic equipment (WEEE) is a matter of concern for governments worldwide. In developing countries, the problem is more complex because municipal waste management is still a challenge for municipalities. Fernando de Noronha Island, an environmentally protected area, has a transfer station for solid waste before it is sent to the final destination abroad, which is different waste management model to most urban areas. In order to check the specifics of management of WEEE, this study aimed to qualitatively and quantitatively evaluate the generation of this type of waste on the main island of Fernando de Noronha, taking into consideration aspects related to consumption habits and handling of waste. During the in situ research, a questionnaire was applied to a sample of 83 households. The results provide a picture of the generation of WEEE for a period of 1 year, when a production of 1.3 tons of WEEE was estimated. Relationships between education level and monthly income and between education level and number of plasma/LCD TVs and washing machines were confirmed. Another important result is that only two socioeconomic variables (monthly income and education level) are related to two recycling behavior variables. In addition, the population and government treat WEEE as ordinary waste, ignoring its contaminant potential. Despite the existence of relevant legislation concerning the treatment and disposal of WEEE, additional efforts will be required by the government in order to properly manage this type of waste on the island.

Pollution characteristics and human health risks of potentially (eco)toxic elements (PTEs) in road dust from metropolitan area of Hefei, China

This study aims to investigate the pollution characteristics of road dust and their associated health risks of potentially toxic elements (PTEs) to humans using array-based risk assessment models described by United States Environmental Protection Agency (USEPA) in a metropolitan area of Hefei, China. Geoaccumulation index (I_geo) was used to describe pollution characteristics of roadside dust in urban, periurban and industrial areas. Results indicate that industrial roadside dust was contaminated with Fe, Ni, Cu, Ti, V, Pb, Ba, Sb, Cr, Sn, Pb, As and Ga showing I_geo value (log₂ (x)) between I_geo class 3 to 4. In other hand, urban roadside dust contamination with Cu, Zn, Sb and Ga ranged between I_geo classes 2 to 3 and with As and Pb ranged between I_geo classes 4 to 5. Furthermore, health risk assessment revealed negligible non-cancerous health hazard in all sites including urban, periurban and industrial areas. The hazard quotient (HQ) and hazard Index (HI) values for all exposure routes (ingestion, inhalation, and dermal contact) were <1 except for chromium with HI value of 1.06E+00 in industrial areas. Moreover, the most prominent exposure route was ingestion (HQ_ing) and the non-carcinogenic health risks were found to be high in case of children compared to the adults. The cancer risk from As, Co, Cr, Ni, and Pb was found to be in safe levels as the RI (carcinogenic risks) values were below the limits for carcinogens (1.00E-6 to 1.00E-4).

Lead exposure is related to hypercortisolemic profiles and allostatic load in Brazilian older adults

Lead levels (Pb) have been linked to both hyper- and hypo-reactivity of hypothalamic-pituitary-adrenal axis (HPA) axis to acute stress in animals and humans. Similarly, allostatic load (AL), the 'wear and tear' of chronic stress, is associated with inadequate HPA axis activity. We examined whether Pb levels would be associated with altered diurnal cortisol profile, as a primary mediator of AL, during aging. Pb levels were measured from blood samples (BPb) of 126 Brazilian individuals (105 women), between 50 and 82 years old. Six neuroendocrine, metabolic, and anthropometric biomarkers were analyzed and values were transformed into an AL index using clinical reference cut-offs. Salivary samples were collected at home over 2 days at awakening, 30-min after waking, afternoon, and evening periods to determine cortisol levels. A multiple linear regression model showed a positive association between BPb as the independent continuous variable and cortisol awakening response (R²=0.128; B=0.791; p=0.005) and overall cortisol concentration (R²=0.266; B=0.889; p<0.001) as the outcomes. Repeated measures ANOVA showed that individuals with high BPb levels showed higher cortisol at 30min after awakening (p=0.003), and in the afternoon (p=0.002) than those with low BPb values. Regarding AL, regression model showed that BPb was positively associated with AL index (R²=0.100; B=0.204; p=0.032). Correlation analyzes with individual biomarkers showed that BPb was positively correlated with HDL cholesterol (p=0.02) and negatively correlated with DHEA-S (p=0.049). These findings suggest that Pb exposure, even at levels below the reference blood lead level for adults recommended by the National Institute for Occupational Safety and Health and by the Center for Disease Control and Prevention, may contribute to AL and dysregulated cortisol functioning in older adults. Considering these findings were based on cross-sectional data future research is needed to confirm our exploratory results.

Trend of childhood blood lead levels in cities of China in recent 10 years

The adverse effects of lead on human especially childhood have been well established. Largely due to the phase out of lead in gasoline, blood lead levels (BLLs) had declined substantially all over the world including China. In 2004, 2007, 2010, and 2013, we conducted a continuous project including 47,346 children aged 0-6 years old from 11 cities all over China to show how the decline happened and to explore what to do next to improve the BLLs of children of China. Our data shown the BLLs of Chinese children decreased from 46.38, 43.58, 38.95 to 37.17 μg/L, but the decline was not enough. These decline was mainly because of the number decrease of children with high BLLs. Integrated strategy should be used to promote the BLLs of Chinese children, like striving to improve the environment, setting new cutoff for high BLLs, and establishing routine blood lead screening.

Temporal and spatial characteristics of lead emissions from the lead-acid battery manufacturing industry in China

An inventory of lead emissions was established for the lead-acid battery (LAB) manufacturing industry in China from 2000 to 2014. The lead emissions from the LAB manufacturing industry increased from 133 t in 2000 to a peak at 281 t in 2010 with the rapid development of LAB industry. Since 2011, a mandatory national clean action on LAB industry and a series of retrofitting measures have been implemented in China. As a result, more than 80% of small and low-efficient LAB manufacturers were closed, and technical-environmental performance of the industry has been improved significantly. Thus the lead emissions from the industry declined to 113 t in 2014. Geographically, lead emissions were attributed to several provinces with intensive LAB manufacturers, including Zhejiang, Guangdong, Jiangsu, Shandong, and Hebei Province. Spatial transfer of the LAB manufacturing industry from developed areas to developing areas in China was manifest due to strict environmental regulation, posing potential environmental risks to the areas undertaking the industry transfer. In light of the effectiveness of the national clean action, the LAB manufacturing industry will reduce lead emissions further by implementing the entry criteria strictly, adopting policy of total lead emissions control, and establishing a long-term regulatory mechanism for LAB manufacturers. The local authorities in some developing areas should improve abilities of environmental supervision and environmental risk prevention to deal with the spillover of lead emissions.

Longitudinal trends of blood lead levels before and after leaded gasoline regulation in Korea

The objective of this study was to verify a change in the longitudinal trend of blood lead levels for the Korean population, before and after the regulation of leaded gasoline- which occurred between 1987 and 1993 in Korea. A total of 77 reports on blood lead levels among general Korean population between 1981 and 2014 were selected, and the results were summarized to have the variables of year, number of subjects, the subjects' range in age, gender, and blood lead concentrations (arithmetic mean). The annual average atmospheric lead levels for four major cities (i.e., Seoul, Busan, Daegu and Gwangju) were collected from the Air Pollution Monitoring Database from 1991, and pilot studies from 1985 to 1990 before the national air quality monitoring system was launched in 1991. Blood lead levels were visualized in a bubble plot in which the size of each bubble represented the sample size of each study, and the annual average concentrations in ambient air were depicted on line graphs. Blood lead levels in the Korean population tended to gradually increase from the early 1980s (approximately 15-20 μg/dL) until 1990-1992 (20-25 μg/dL). Blood lead levels then began to rapidly decrease until 2014 (<2 μg/dL). Similar patterns were observed for both adults (≥20 years) and younger children/adolescents. The same longitudinal trend was observed in annual average atmospheric lead concentration, which suggests a significant correlation between air lead concentration and blood lead concentration in the general population. In conclusion, the regulation of leaded gasoline has significantly contributed to the rapid change in blood lead concentrations. And, the regulation of other sources of lead exposure should be considered to further decrease blood lead levels in the Korean population.

Associations of blood lead levels with reproductive hormone levels in men and postmenopausal women: Results from the SPECT-China Study

We examined whether blood lead levels (BLLs) were associated with reproductive hormone levels in a cross-sectional study using data from the SPECT-China study. We selected 2286 men and 1571 postmenopausal women without hormone replacement therapy. BLLs, blood cadmium, total testosterone (TT), oestradiol (E2), luteinizing hormone (LH), follicle stimulating hormone (FSH) and sex hormone binding globulin(SHBG) levels were measured. The results showed that median values (interquartile range) of BLLs were 44.00 μg/L (29.00–62.30) for men and 41.00 μg/L (27.00–59.81) for postmenopausal women. In linear regression, after adjusting for age, current smoking status, body mass index, systolic blood pressure, diabetes and blood cadmium level, TT (P for trend = 0.001) and SHBG (P for trend < 0.001) levels were still positively associated with BLLs in men. Meanwhile, significant positive associations were found for BLLs with SHBG (P for trend = 0.002), FSH (P for trend = 0.001) and LH (P for trend = 0.026) levels in postmenopausal women. Additionally, the association between BLL and SHBG was modified by dysglycaemia (P for interaction = 0.03) in postmenopausal women. In conclusion, BLLs were associated with reproductive hormone levels in the general population of Chinese men and postmenopausal women, which may have important implications for human health. Concerted efforts to reduce adult lead exposure are warranted.

Heavy metal contaminations in soil-rice system: source identification in relation to a sulfur-rich coal burning power plant in Northern Guangdong Province, China

Heavy metal contents (As, Cd, Cr, Cu, Hg, Ni, Pb, and Zn) in 99 pairs of soil-rice plant samples were evaluated from the downwind directions of a large thermal power plant in Shaoguan City, Guangdong Province, China. Results indicate that there is a substantial buildup of As, Cd, Cu, Pb, and Zn in the predominant wind direction of the power plant. The significant correlations between S and heavy metals in paddy soil suggest that the power plant represents a source of topsoil heavy metals in Shaoguan City due to sulfur-rich coal burning emissions. Elevated Cd concentrations were also found in rice plant tissues. Average Cd (0.69 mg kg(-1)) and Pb (0.39 mg kg(-1)) contents in rice grain had exceeded their maximum permissible limits (both were 0.2 mg kg(-1)) in foods of China (GB2762-2005). The enrichment of Cd and Pb in rice grain might pose a potential health risk to the local residents.

Trace metals in resuspended fraction of settled bus dust and assessment of non-occupational exposure

Trace metals (TMs) within urban public transportation systems have rarely been studied and information on related health risks is scant. This study measured TM (arsenic, chromium, cadmium, nickel, zinc, copper and lead) concentrations in resuspended fractions of settled bus dust in Harbin, China, and estimated the exposure and health risks. The incremental lifetime cancer risk (ILCR) for commuters was estimated for TM exposures. The average concentration of total TMs was 559μg/g (ranges from 312 to 787) among 45 bus routes in Harbin. The hazard quotient of three selected commuter groups increased in the following order: teenagers<children<adults. Pb had the highest hazard index among six non-carcinogenic risk TMs. The ILCR for passengers was estimated for TM exposure and was shown to be acceptable (1.00E-07-1.00E-05); the sequence of ILCR assessments followed this ascending trend: ingestion>dermal contact>inhalation.

Bioaccessibility, sources and health risk assessment of trace metals in urban park dust in Nanjing, Southeast China

Arsenic, Cd, Co, Cr, Cu, Mn, Ni, Pb, V, and Zn total concentrations and bioaccessibilities in 15 urban park dust samples were determined. The oral bioaccessibility measured by the Simple Bioaccessibility Extraction Test (SBET) decreased in the order of Pb>Cd>Zn>Mn>Cu>Co>V>Ni>As>Cr. The Tomlinson pollution load index (PLI) and geoaccumulation index (I(geo)) were calculated to evaluate the pollution extent to which the samples were contaminated. Sources were identified using principal component analysis and Pb isotope compositions. Most elements except Co and V were considered to mainly originate from anthropogenic sources. Non-carcinogenic and carcinogenic risks to humans through urban park dust exposure were assessed using the oral bioaccessibilities of the elements. Ingestion was the main pathway for non-carcinogenic risk. The hazard quotients were below the safe level (=1) for all elements, however, Pb (0.154) and As (0.184) posed potential higher risks to children than adults. The carcinogenic effects occurring were below the acceptable level (10(-4)) for As and <10(-6) for Cd, Co, Cr, and Ni.

The History, Status, Gaps, and Future Directions of Neurotoxicology in China

BACKGROUND

Rapid economic development in China has produced serious ecological, environmental, and health problems. Neurotoxicity has been recognized as a major public health problem. The Chinese government, research institutes, and scientists conducted extensive studies concerning the source, characteristics, and mechanisms of neurotoxicants.

OBJECTIVES

This paper presents, for the first time, a comprehensive history and review of major sources of neurotoxicants, national bodies/legislation engaged, and major neurotoxicology research in China.

METHODS

Peer-reviewed research and pollution studies by Chinese scientists from 1991 to 2015 were examined. PubMed, Web of Science and Chinese National Knowledge Infrastructure (CNKI) were the major search tools.

RESULTS

The central problem is an increased exposure to neurotoxicants from air and water, food contamination, e-waste recycling, and manufacturing of household products. China formulated an institutional framework and standards system for management of major neurotoxicants. Basic and applied research was initiated, and international cooperation was achieved. The annual number of peer-reviewed neurotoxicology papers from Chinese authors increased almost 30-fold since 2001.

CONCLUSIONS

Despite extensive efforts, neurotoxicity remains a significant public health problem. This provides great challenges and opportunities. We identified 10 significant areas that require major educational, environmental, governmental, and research efforts, as well as attention to public awareness. For example, there is a need to increase efforts to utilize new in vivo and in vitro models, determine the potential neurotoxicity and mechanisms involved in newly emerging pollutants, and examine the effects and mechanisms of mixtures. In the future, we anticipate working with scientists worldwide to accomplish these goals and eliminate, prevent and treat neurotoxicity.

CITATION

Cai T, Luo W, Ruan D, Wu YJ, Fox DA, Chen J. 2016. The history, status, gaps, and future directions of neurotoxicology in China. Environ Health Perspect 124:722-732; http://dx.doi.org/10.1289/ehp.1409566.

Uncovering the Evolution of Lead In-Use Stocks in Lead-Acid Batteries and the Impact on Future Lead Metabolism in China

This study aims to illustrate the evolution of lead in-use stocks, particularly in lead-acid batteries (LABs), and their impact on future lead metabolism in China. First, we used a bottom-up methodology to study the evolution of lead in-use stocks in China from 2000 to 2014. It was found that the lead in-use stocks increased from 0.91 to 7.75 Mt. The principal driving force of such change is the rapid development of LABs-driven electric vehicles. Then, we proposed three scenarios, low, baseline, and high in-use stocks, to project the lead demand and supply toward 2030. The results show that the LAB demand will decrease as a result of competition and replacement by lithium ion batteries. The lead demand in China will come to a peak around 2018-2020 under the three scenarios, then reduce to 3.7, 4.6, and 5.3 Mt/yr in 2030. Meanwhile, primary lead outputs will follow the increase of zinc production in China. Secondary lead recovered from spent LABs will also increase gradually. The overall unused lead stocks in 2030 will be 49.6, 44.8, and 41.2 Mt under the three scenarios, some 3.5-5.7 times as big as the lead in-use stocks. Thus, a large amount of lead will have to be safely stockpiled or exported in China.

Exposure risk of young population to lead: A case study in Le'an River Basin in Jiangxi Province, China

Blood lead (Pb) level of children has widely been attracting public concern in China, particularly in the sites near mining or industrial areas. However, the policies about how to efficiently reduce the Pb intake of children are still under discussion. We collected six food types based on the local dietary habits and soils from Dexing, Leping, and Poyang Counties situated along the Le'an River Basin from upstream to downstream, and their Pb contents were analyzed. A Monte Carlo model was used to simulate the dietary chronic daily intake of Pb (CDIPb) from various foods and ingested soil by hand-to-mouth activities and its non-carcinogenic risk to children indicated by hazard quotient (HQ). Only in the rural area of Dexing, its soil and vegetables both had higher Pb content than the national tolerance limits of China, resulting its the highest CDIPb among all the areas. The Pb contents of the six food types and soils in other sites were overall below the limits. Vegetables and rice accounted for from 63% (Leping, urban) to 85% (Dexing, rural) of the total CDIPb and ingested soil overall took up ∼6%. In the rural area, Dexing had the highest proportion (82.8%) of children with HQ > 1, followed by Leping (36.1%) and Poyang (27.7%). Different order was found in the urban areas, i.e. Dexing (46.7%) > Poyang (41.0%) > Leping (26.4%). Vegetables and rice were overall the two major contributors to the total CDI of Pb, which should be focused on to control the Pb intake by the local children, especially for those living in the rural area of Dexing County.

Improving Knowledge about Children's Environmental Health in Northwest China

The main purpose of this study was to identify policy maker opinions and attitudes towards children’s environmental health (CEH), potential barriers to child-specific protective legislation and implementation in northwest China, and evaluate knowledge and attitudes about CEH before and after an educational conference. We conducted seventy-two interviews with regional officials, researchers and non-governmental organization representatives from five provinces, and surveyed participants (forty-seven) before and after an educational conference in northwest China about CEH. Interviews identified general consensus among participants of the adverse effects of air pollution on children, yet few participants knew of policies to protect them. Barriers identified included limited funding and enforcement, weak regional governments and absence of child-specific policy-making. After the conference, substantially greater self-efficacy was identified for lead, mercury, air pollution and polychlorinated biphenyls (+0.57–0.72 on a 1–5 Likert scale, p = 0.002–0.013), and the scientific knowledge for the role of environment in children’s health (+0.58, p = 0.015), and health care provider control (+0.52, p = 0.025) were rated more strongly. We conclude that policy makers in Northwest China appreciate that children are uniquely vulnerable, though additional regulations are needed to account for that vulnerability. Further research should examine effectiveness of the intervention on a larger scale and scope, and evaluate the usefulness of such interventions in translating research into improved care/reduced exposure to environmental hazards.

Lead in Chinese villager house dust: Geographical variation and influencing factors

House dust has been recognized as an important contributor to Pb exposure of children. Here we conducted a comprehensive study to investigate geographical variation of Pb in Chinese villager house dust. The influences of outdoor soil Pb concentrations, dates of construction, house decoration materials, heating types, and site specific pollution on Pb concentrations in house dust were evaluated. The concentrations of Pb in 477 house dust samples collected from twenty eight areas throughout China varied from 12 to 2510 mg/kg, with a median concentration of 42 mg/kg. The median Pb concentrations in different geographical areas ranged from 16 (Zhangjiakou, Hebei) to 195 mg/kg (Loudi, Hunan). No correlations were found between the house dust Pb concentrations and the age of houses, as well as house decoration materials. Whereas outdoor soil, coal combustion, and site specific pollution may be potential Pb sources. Principal component analysis (PCA) confirmed that elemental compositions of the house dust were controlled by both anthropogenic and geogenic sources. Using scanning electron microscopy (SEM), the Pb bearing particles in the house dust were also studied.

The characteristic of Pb isotopic compositions in different chemical fractions in sediments from Three Gorges Reservoir, China

To explore the distribution and sources of Pb within the Three Gorges Reservoir (TGR), Pb concentrations and isotope ratios were measured in sediment cores collected from one mainstream and three tributaries. The results showed that sediments contained an average of 43.54 mg kg(-1) of Pb, roughly 1.6 times higher than the geochemical background concentration. Mainstream sediments showed higher average Pb concentrations but slightly less (206)Pb/(207)Pb and more radiogenic (207)Pb/(208)Pb ratios than all tributaries. Most Pb occurred in reducible phases, with much less in exchangeable and oxidizable fractions; thus, Fe-Mn oxides may be the major sink of anthropogenic Pb. Bi-plots of (206)Pb/(207)Pb versus Pb content, and of (206)Pb/(207)Pb versus (207)Pb/(208)Pb, indicated that coal combustion was the predominant anthropogenic Pb source for exchangeable, reducible, and oxidizable fractions, while residual Pb mainly occurred naturally. The average percentage of coal consumption contribution was 61.1% for the Pb contamination in sediments in the lower reaches in the TGR region.

Relationship of lead and essential elements in whole blood from school-age children in Nanning, China

OBJECTIVES

The aim of this study was to investigate blood lead level and its relationship to essential elements (zinc, copper, iron, calcium and magnesium) in school-age children from Nanning, China.

METHODS

A total of 2457 children aged from 6 to 14 years were enrolled in Nanning, China. The levels of lead (Pb), zinc (Zn), copper (Cu), iron (Fe), calcium (Ca) and magnesium (Mg) were determined by an atomic absorption spectrometer.

RESULTS

The mean blood lead level (BLL) was 57.21±35.00μg/L. 188 (7.65%) asymptomatic children had toxic lead level higher than 100μg/L. The school-age boys had similar lead level among different age groups, while the elder girls had less BLL. The blood Zn and Fe were found to be increased in the boys with elevated BLL, but similar trends were not observed in the girls. Positive correlations between Pb and Fe or Mg (r=0.112, 0.062, respectively, p<0.01) and a negative correlation between Pb and Ca (r=-0.047, p<0.05) were further established in the studied children.

CONCLUSIONS

Lead exposure in school-age children was still prevalent in Nanning. The boys and girls differed in blood levels of lead and other metallic elements. Lead exposure may induce metabolic disorder of other metallic elements in body.

The trend of lead poisoning rate in Chinese population aged 0-18 years old: a meta-analysis

BACKGROUND

Childhood lead poisoning is a public health problem gained widely attention for the health damage caused by lead exposure. Pediatrics defines lead poisoning as BLL of or higher than 10 μg/dL, which leads to harmful effects in nervous system, hematological system and urinary system. This study investigates the percentage of 0-18 year old Chinese population with blood lead level (BLL) ≥10 μg/dL during 1990-2012 by searching epidemiologic studies from electronic database focused on BLL in mainland China.

METHODS

Epidemiologic studies about BLL in China mainland between January 1990 and October 2012 were searched from electronic databases including CNKI, CBM disc, Wanfang Data, Pubmed and Medline. Data extraction, data analysis and risk of bias assessments were performed.

RESULTS

Fifty-five articles were included in analysis containing 200,002 subjects, covering 19 provinces, autonomous regions and municipalities. The corrected pooled rate by trim and fill method under random effect model was 9 % (95 CI: 6 %, 12 %). The corrected pooled lead poisoning rate by trim and fill method was 28.1 % (95 % CI: 21.6 %, 34.6 %) from data published during 1990-2000, much higher than the rate during 2001-2005 (10.5 %, 95 % CI: 6.4 %, 14.5 %) and the rate during 2006-2012 (5.3 %, 95 % CI: 3.7 %, 7 %). The corrected pooled lead poisoning percentage in eastern zone (4.3 %, 95 % CI: 2 %, 6.6 %) was slightly lower than that in western zone (5.8 %, 95 % CI: 3.2 %, 8.5 %) and much lower than in central zone (8.5 %, 95 % CI: 4.9 %, 12.1 %). The corrected pooled rate of population living around mining area (70 %, 95 % CI: 62.7 %, 77.3 %) was much higher than that of population in urban area (9.6 %, 95 % CI: 7.1 %, 12.1 %), suburban area (23.6 %, 95 % CI: 17 %, 30.3 %), rural area (23.8 %, 95 % CI: 6.7 %, 40.9 %) and industrial area (57.5 %, 95 % CI: 28 %, 86.9 %). In male population, the corrected pooled rate (10 %, 95 % CI: 7 %, 13 %) was slightly higher than that in female population (7.7 %, 95 % CI: 5 %, 10.4 %). Considering different age groups, the lead poisoning prevalence gradually rose with the increase of age and reached peak level at preschool age, then declined slightly with age.

CONCLUSION

This meta-analysis revealed lead exposure situation of Chinese population in recent decades which provide robust evidence for policy making.

Characteristics of Bacillus sp. PZ-1 and its biosorption to Pb(II)

During the long and cold winter season in northern area of China, wastewater treatment is often inefficient which causes the substandard discharge. In this study, a lead-resistant psychrotrophilic bacterium was isolated and used as an adsorbent to remove Pb(II) from aqueous solution at 15 °C. The strain was identified and designated as Bacillus sp. PZ-1 based on the morphology, physiological-biochemical experiments and 16S rDNA sequence analysis. The minimal inhibitory concentration and antibiotic experiments revealed that PZ-1 had high resistance to 1500 mg L(-1) of Zn(II), 800 mg L(-1) of Cu(II), 400 mg L(-1) of Ni(II), 15 µg mL(-1) of chloramphenicol and 50 µg mL(-1) of streptomycin, but susceptibility to 200 mg L(-1) of Co(II). Scanning electron microscopy, energy dispersive X-ray spectroscopy and atomic force microscopy analyses showed that biosorption of Bacillus sp. PZ-1 to Pb(II) involved surface adsorption, ion exchange and micro-precipitate. Fourier transform infrared spectroscopy analyses indicated that hydroxyl, carbonyl and carboxyl on cells may play vital roles in Pb(II) adsorption. Besides, siderophore secreted by PZ-1 had beneficial impacts on the Pb(II) removal. Biosorption experiments were carried out as a function of initial Pb(II) concentration (50-500 mg L(-1)), pH (3.0-7.0), biomass concentration (5-50 g L(-1)) and contact time (5-40 min). Biosorption rate of 93.01% with adsorption capacity of 9.30 mg g(-1) was obtained under the initial Pb(II) concentration of 400 mg (-1), pH of 5.0, contact time of 20 min, biomass concentration of 40 g L(-1) and the temperature of 15 °C. The equilibrium data were well fitted with Langmuir model, which indicated the adsorption process of Pb(II) is monolayer adsorption. Bacillus sp. PZ-1 appeared to be an efficient biosorbent for removing Pb(II) from wastewater at low temperature.

Baseline blood levels of manganese, lead, cadmium, copper, and zinc in residents of Beijing suburb

Baseline blood concentrations of metals are important references for monitoring metal exposure in environmental and occupational settings. The purpose of this study was to determine the blood levels of manganese (Mn), copper (Cu), zinc (Zn), lead (Pb), and cadmium (Cd) among the residents (aged 12-60 years old) living in the suburb southwest of Beijing in China and to compare the outcomes with reported values in various developed countries. Blood samples were collected from 648 subjects from March 2009 to February 2010. Metal concentrations in the whole blood were determined by ICP-MS. The geometric means of blood levels of Mn, Cu, Zn, Pb and Cd were 11.4, 802.4, 4665, 42.6, and 0.68 µg/L, respectively. Male subjects had higher blood Pb than the females, while the females had higher blood Mn and Cu than the males. There was no gender difference for blood Cd and Zn. Smokers had higher blood Cu, Zn, and Cd than nonsmokers. There were significant age-related differences in blood levels of all metals studied; subjects in the 17-30 age group had higher blood levels of Mn, Pb, Cu, and Zn, while those in the 46-60 age group had higher Cd than the other age groups. A remarkably lower blood level of Cu and Zn in this population as compared with residents of other developed countries was noticed. Based on the current study, the normal reference ranges for the blood Mn were estimated to be 5.80-25.2 μg/L; for blood Cu, 541-1475 μg/L; for blood Zn, 2349-9492 μg/L; for blood Pb, <100 μg/L; and for blood Cd, <5.30 μg/L in the general population living in Beijing suburbs.

Health risk assessment of various metal(loid)s via multiple exposure pathways on children living near a typical lead-acid battery plant, China

Manufacture of lead-acid batteries is of widespread interest because of its emissions of heavy metals and metalloids into environment, harming environmental quality and consequently causing detrimental effects on human health. In this study, exposure pathways and health risks of children to heavy metal(loid)s (Pb, Cd, As, etc) were investigated based on field sampling and questionnaire. Pb was one of the most abundant elements in children's blood, with an elevated blood lead level of 12.45 μg dL(-1). Soil/dust and food were heavily polluted by targeted metal(loid)s. Food ingestion accounted for more than 80% of the total exposure for most metal(loid)s. The non-cancer risks to children were 3-10 times higher than the acceptable level of 1, while the cancer risks were 5-200 times higher than the maximum acceptable level of 1.0 × 10(-4). The study emphasized the significance of effective environmental management, particularly to ensure food security near battery facilities.

Childhood lead exposure in an industrial town in China: coupling stable isotope ratios with bioaccessible lead

Fingerprinting based on stable isotopes of lead (Pb) in blood and environmental media helps to identify Pb exposure pathways in children. However, previous studies used stable isotopes of total Pb in media. In this study, a wire rope production town in China (Zhuhang) was selected for investigating the effectiveness of using isotope ratios in bioaccessible Pb to identify childhood Pb exposure pathways. Blood Pb levels of 115 children in Zhuhang were 1.7-20.4 μg dL(-1), averaging 6.1 ± 3.2 μg dL(-1) (mean ± standard deviation), and were ∼1.6 times the national average in China (3.9 ± 1.8 μg dL(-1)). Among different environmental media (housedust, soil, PM10, vegetables, rice, and drinking water), housedust (695 ± 495 mg kg(-1)) and vegetables [0.36 ± 0.40 mg (kg of fresh weight)(-1)] contained elevated Pb concentrations. The isotope ratios ((207)Pb/(206)Pb and (208)Pb/(206)Pb) of total Pb were the highest in housedust (0.8587 ± 0.0039 and 2.1049 ± 0.0087) but lower than blood Pb ratios (0.8634 ± 0.0027 and 2.1244 ± 0.0061). When using bioaccessible Pb in housedust (0.8639 ± 0.0018 and 2.1171 ± 0.0036), the isotope ratios overlapped with blood Pb ratios, suggesting that incidental ingestion of housedust was the predominant contributor to children's blood Pb. Coupling the stable isotope technique with bioaccessible Pb is more reliable for identifying Pb exposure pathways than total Pb determinations.

Assessment of regional human health risks from lead contamination in Yunnan province, southwestern China

Identification and management the 'critical risk areas' where hotspot lead exposures are a potential risk to human health, become a major focus of public health efforts in China. But the knowledge of health risk assessment of lead pollution at regional and national scales is still limited in China. In this paper, under the guidance of 'sources-pathways-receptors' framework, regional human health risk assessment model for lead contamination was developed to calculate the population health risk in Yunnan province. And the cluster and AHP (analytic hierarchy process) analysis was taken to classify and calculate regional health risk and the decomposition of the regional health risk in the greatest health risk region, respectively. The results showed that Yunnan province can be divided into three areas. The highest health risk levels, located in northeastern Yunnan, including Kunming, Qujing, Zhaotong region. In those regions, lead is present at high levels in air, food, water and soil, and high population density which pose a high potential population risk to the public. The current study also reveals that most regional health risk was derived from the child receptors (age above 3 years) 4.3 times than the child receptors (age under 3 years), and ingestion of lead-contaminated rice was found to be the most significant contributor to the health risk (accounting for more than 49% health risk of total). This study can provide a framework for regional risk assessment in China and highlighted some indicators and uncertainties.

Blood lead levels in children aged 0-6 years old in Hunan Province, China from 2009-2013

Objectives

The aim of this study is to describe blood lead levels (BLLs) and the prevalence of elevated blood lead levels (EBLLs) in children aged 0–6 years old and to analyze the BLL trend in children from 2009 to 2013 in China.

Methods

A total of 124,376 children aged 0–6 years old were recruited for this study from January 1^st 2009 to December 31^st 2013. Their blood lead levels were analyzed using atomic absorption spectrometry.

Results

The median BLL was 64.3 μg/L (IQR: 49.6–81.0), and the range was 4.3–799.0 μg/L. Blood lead levels were significantly higher in boys (66.0 μg/L) than in girls (61.9 μg/L) (P<0.001). The overall prevalence of BLLs≥100 μg/L was 10.54% in children aged 0–6 years in Hunan Province. Between 2009 and 2013, the prevalence of EBLLs (≥100 μg/L) decreased from 18.31% to 4.26% in children aged 0–6 years and increased with age. The prevalence of EBLLs has dramatically decreased in two stages (2009–2010 and 2012–2013), with a slight fluctuation in 2010 and 2011.

Conclusions

Both BLLs and the prevalence of EBLLs in children aged 0–6 years old declined substantially from 2009 to 2013 in Hunan Province; however, both remain at unacceptably high levels compared to developed countries. Comprehensive strategies are required to further reduce blood lead levels in children.

Levels and source apportionment of children's lead exposure: could urinary lead be used to identify the levels and sources of children's lead pollution?

As a highly toxic heavy metal, the pollution and exposure risks of lead are of widespread concern for human health. However, the collection of blood samples for use as an indicator of lead pollution is not always feasible in most cohort or longitudinal studies, especially those involving children health. To evaluate the potential use of urinary lead as an indicator of exposure levels and source apportionment, accompanying with environmental media samples, lead concentrations and isotopic measurements (expressed as (207)Pb/(206)Pb, (208)Pb/(206)Pb and (204)Pb/(206)Pb) were investigated and compared between blood and urine from children living in the vicinities of a typical coking plant and lead-acid battery factory. The results showed urinary lead might not be a preferable proxy for estimating blood lead levels. Fortunately, urinary lead isotopic measurements could be used as an alternative for identifying the sources of children's lead exposure, which coincided well with the blood lead isotope ratio analysis.

Association of blood lead levels with methylenetetrahydrofolate reductase polymorphisms among Chinese pregnant women in Wuhan city

BACKGROUND

Pregnancy is an important stimulus of bone lead release. Elevated blood lead levels (BLLs) may cause adverse pregnancy outcomes for mothers and harmful lead effects on fetuses. However, the reports about maternal BLL changes during pregnancy are conflicting to some extent. This article is to explore the variations in BLLs among pregnant women. The relationships of BLLs with methylenetetrahydrofolate reductase (MTHFR) gene C677T, A1298C, and G1793A polymorphisms, which are associated with bone resorption, were also studied. A total of 973 women, including 234, 249, and 248 women in their first, second, and third trimesters, respectively, and 242 non-pregnant women, were recruited at the Wuhan Women and Children Medical Health Center.

METHODS

BLLs were determined using a graphite furnace atomic absorption spectrometer. Single-nucleotide polymorphisms of MTHFR were identified with the TaqMan probe method.

RESULTS

The geometric mean (geometric standard deviation) of BLLs was 16.2 (1.78) μg/L for all participants. All the studied MTHFR alleles were in Hardy-Weinberg equilibrium. Multiple-linear regression analysis revealed the following results. Among the pregnant women, those that carried MTHFR 677CC (i.e. wild-genotype homozygote) and 1298CC (i.e. mutant-genotype homozygote) exhibited higher BLLs than those that carried 677CT/TT (standardized β = 0.074, P = 0.042) and 1298AC/AA (standardized β = 0.077, P = 0.035) when other covariates (e.g., age, no. of children, education and income, etc.) were adjusted. The BLLs of pregnant women consistently decreased during the pregnancy and these levels positively correlated with BMI (standard β = 0.086-0.096, P<0.05).

CONCLUSIONS

The 1298CC mutant-type homozygote in the MTHFR gene is a risk factor for high BLLs among low-level environmental lead-exposed Chinese pregnant women, whose BLLs consistently decreased during gestation.

Assessment of lead bioaccessibility in soils around lead battery plants in East China

Soil ingestion is an important human exposure pathway for lead (Pb). A modified physiologically based extraction test was applied to 70 soil samples from five battery plants in East China. The mean values for soil pH, soil organic matter, Fe and Mn concentrations ranged from 5.9% to 8.1, 0.37% to 2.2%, 2.78% to 3.75%, and 507-577 mg kg(-1), respectively, while Pb concentrations ranged widely in 14.3-2000 mg kg(-1). The isotopic ratios of 14 soils from one of the five battery plants formed a straight line in the plot of (208)Pb/(206)Pb vs. (207)Pb/(206)Pb, indicating Pb emissions from the lead battery plant as the dominant anthropogenic source within 200 m. Lead bioaccessibility in the soils ranged from 4.1% to 66.9% in the gastric phase and from 0.28% to 9.29% in the gastrointestinal phase. Multiple step regressions identified modes as BAgastric=-106.8+0.627[Pb]+19.1[Fe]+11.3[SOM], and BAgastrointestinal=-2.852+0.078[Pb].

Isotopic ratio based source apportionment of children's blood lead around coking plant area

Lead exposure in the environment is a major hazard affecting human health, particularly for children. The blood lead levels in the local children living around the largest coking area in China were measured, and the source of blood lead and the main pathways of lead exposure were investigated based on lead isotopic ratios ((207)Pb/(206)Pb and (208)Pb/(206)Pb) in blood and in a variety of media, including food, airborne particulate matter, soil, dust and drinking water. The children's blood lead level was 5.25 (1.59 to 34.36 as range) μg dL(-1), lower than the threshold in the current criteria of China defined by the US Centers for Disease Control (10 μg dL(-1)). The isotopic ratios in the blood were 2.111±0.018 for (208)Pb/(206)Pb and 0.864±0.005 for (207)Pb/(206)Pb, similar to those of vegetables, wheat, drinking water, airborne particulate matter, but different from those of vehicle emission and soil/dust, suggesting that the formers were the main pathway of lead exposure among the children. The exposure pathway analysis based on the isotopic ratios and the human health risk assessment showed that dietary intake of food and drinking water contributed 93.67% of total exposed lead. The study further indicated that the coal used in the coking plant is the dominant pollution source of lead in children's blood.

Effect of lead pollution control on environmental and childhood blood lead level in Nantong, China: an interventional study

Children's blood lead levels and prevalence of lead poisoning in China are significantly higher than in developed countries, though a substantial decrease has been observed. Since 2011, strict lead control policies in lead-related industries have been implemented in China, but the success of these policies is unknown. In this study, we collected environmental samples, questionnaire data, and blood samples from 106 children from 1 to 14 years old, before and after implementation of lead-usage control policy in wire rope factories by local government in Zhuhang, Nantong in 2012. Results showed that, one year after the lead control, lead concentrations sharply decreased in both environmental and biological samples with a decrease of 0.43 μg/m3 (-84.3%) in ambient air samples, 0.22 mg/kg (-36.1%) in vegetable samples, 441.1 mg/kg (-43.7%) in dust samples, and 6.24 μg/dL (-51.5%) in childhood blood lead levels (BLL). This study demonstrates the success of lead control policies in promoting the prevention and control of childhood lead poisoning in Nantong, China.

Biochar from Alternanthera philoxeroides could remove Pb(II) efficiently

A novel bio-adsorbent was successfully synthesized by pyrolyzing Alternanthera philoxeroides (AP), one of the most widely used hydrophytes for eutrophic lake ecological restoration under O2-limited condition at 600 °C. Compared with commercially active carbon (AC), the initial solution pH had a weak effect on the adsorption of Pb(II) by AP biochar (APB). The maximum adsorption capacity of APB for Pb(II) was 257.12 mg/g, which was 5.3 times of that of the AC. The adsorption process was fast, with only 2.5h to reach adsorption equilibrium. The adsorption mechanism of Pb(II) by APB involves the precipitation and complexation of Pb(II) with free carboxyl/hydroxyl functional groups and mineral carbonates of APB as well as ion replacement between Pb(II) and alkaline earth cations. These results suggest that using a low-cost APB adsorbent for heavy metals contaminated water treatment may have great ecological and environmental significance.

Description of 3,180 courses of chelation with dimercaptosuccinic acid in children ≤ 5 y with severe lead poisoning in Zamfara, Northern Nigeria: a retrospective analysis of programme data

BACKGROUND

In 2010, Médecins Sans Frontières (MSF) discovered extensive lead poisoning impacting several thousand children in rural northern Nigeria. An estimated 400 fatalities had occurred over 3 mo. The US Centers for Disease Control and Prevention (CDC) confirmed widespread contamination from lead-rich ore being processed for gold, and environmental management was begun. MSF commenced a medical management programme that included treatment with the oral chelating agent 2,3-dimercaptosuccinic acid (DMSA, succimer). Here we describe and evaluate the changes in venous blood lead level (VBLL) associated with DMSA treatment in the largest cohort of children ≤ 5 y of age with severe paediatric lead intoxication reported to date to our knowledge.

METHODS AND FINDINGS

In a retrospective analysis of programme data, we describe change in VBLL after DMSA treatment courses in a cohort of 1,156 children ≤ 5 y of age who underwent between one and 15 courses of chelation treatment. Courses of DMSA of 19 or 28 d duration administered to children with VBLL ≥ 45 µg/dl were included. Impact of DMSA was calculated as end-course VBLL as a percentage of pre-course VBLL (ECP). Mixed model regression with nested random effects was used to evaluate the relative associations of covariates with ECP. Of 3,180 treatment courses administered, 36% and 6% of courses commenced with VBLL ≥ 80 µg/dl and ≥ 120 µg/dl, respectively. Overall mean ECP was 74.5% (95% CI 69.7%-79.7%); among 159 inpatient courses, ECP was 47.7% (95% CI 39.7%-57.3%). ECP after 19-d courses (n = 2,262) was lower in older children, first-ever courses, courses with a longer interval since a previous course, courses with more directly observed doses, and courses with higher pre-course VBLLs. Low haemoglobin was associated with higher ECP. Twenty children aged ≤ 5 y who commenced chelation died during the period studied, with lead poisoning a primary factor in six deaths. Monitoring of alanine transaminase (ALT), creatinine, and full blood count revealed moderate ALT elevation in <2.5% of courses. No clinically severe adverse drug effects were observed, and no laboratory findings required discontinuation of treatment. Limitations include that this was a retrospective analysis of clinical data, and unmeasured variables related to environmental exposures could not be accounted for.

CONCLUSIONS

Oral DMSA was a pharmacodynamically effective chelating agent for the treatment of severe childhood lead poisoning in a resource-limited setting. Re-exposure to lead, despite efforts to remediate the environment, and non-adherence may have influenced the impact of outpatient treatment. Please see later in the article for the Editors' Summary.

The national trend of blood lead levels among Chinese children aged 0-18 years old, 1990-2012

We analyzed the epidemiological data during 1990-2012 that investigated the blood lead level (BLL) in the population aged 0-18 years old in China mainland and provided evidence of the benefits of implementing policies to prevent lead pollution based on the dynamic changes of BLL. Data were collected through databases including China Knowledge Resource Integrated Database (CNKI), CBM disc, Wanfang Data, Pubmed and Medline. The inclusion criteria were: 1. Epidemiological study in healthy population not included studies limited to specific patient; 2. Study subject was not the specific lead exposure population; 3. Sample size should be no less than 100 (for neonatal, no less than 50); 4. BLL detection was under strict quality control; and 5. Results should be presented as BLL (arithmetic mean level or geometric mean level). 62 articles were included in this study. All the surveys in these articles contained 189,352 subjects in 19 provinces, autonomous regions and municipalities. Linear regression analysis showed a significant decrease between 1990 and 2012 with an estimated regression coefficient of 3.05/year (SE=0.01, p<0.001). BLL gradually declined since early 21st century. Median levels of BLL among the three economic zones were 51.4 μg/L in the eastern zone, 52.72 μg/L in the central zone and 46.2 μg/L in the western zone respectively. Median BLLs in male and female population aged 0-18 years old of China were 48.8 μg/L and 46.1μg/L. Median levels of BLL among the different age ranges were 74.9 μg/L in newborn, 46.4 μg/L in 0 to 3 years old, 57.6 μg/L in 3 to 7 years old and 55.6 μg/L in above 7 years old respectively. In conclusion, the BLL in the Chinese population of 0-18 years old has gradually dropped in the past 10 years. The decline in temporal trend still remains under potential impacts of several factors such as economical level, gender and age difference. Although, China has made significant achievements in the control prevention of lead pollution, concerted efforts are still warranted to reduce children lead poisoning.

Source of atmospheric heavy metals in winter in Foshan, China

Foshan is a ceramics manufacturing center in the world and the most polluted city in the Pearl River Delta (PRD) in southern China measured by the levels of atmospheric heavy metals. PM2.5 samples were collected in Foshan in winter 2008. Among the 22 elements and ions analyzed, 7 heavy metals (Zn, V, Mn, Cu, As, Cd and Pb) were studied in depth for their levels, spatiotemporal variations and sources. The ambient concentrations of the heavy metals were much higher than the reported average concentrations in China. The levels of Pb (675.7 ± 378.5 ng/m(3)), As (76.6 ± 49.1 ng/m(3)) and Cd (42.6 ± 45.2 ng/m(3)) exceeded the reference values of NAAQS (GB3095-2012) and the health guidelines of the World Health Organization. Generally, the levels of atmospheric heavy metals showed spatial distribution as: downtown site (CC, Chancheng District)>urban sites (NH and SD, Nanhai and Shunde Districts)>rural site (SS, Shanshui District). Two sources of heavy metals, the ceramic and aluminum industries, were identified during the sampling period. The large number of ceramic manufactures was responsible for the high levels of atmospheric Zn, Pb and As in Chancheng District. Transport from an aluminum industry park under light north-west winds contributed high levels of Cd to the SS site (Shanshui District). The average concentration of Cd under north-west wind was 220 ng/m(3), 20.5 times higher than those under other wind directions. The high daily maximum enrichment factors (EFs) of Cd, Pb, Zn, As and Cu at all four sites indicated extremely high contamination by local emissions. Back trajectory analysis showed that the heavy metals were also closely associated with the pathway of air mass. A positive matrix factorization (PMF) method was applied to determine the source apportionment of these heavy metals. Five factors (industry including the ceramic industry and coal combustion, vehicle emissions, dust, transportation and sea salt) were identified and industry was the most important source of atmospheric heavy metals. The present paper suggests a control policy on the four heavy metals Cd, Pb, Zn, and Cu, and suggests the inclusion of As in the ceramic industry emission standard in the future.

The impact of the environment on health in Mongolia: a systematic review

Mongolia has significant exposure to environmental risk factors because of poor environmental management and behaviors, and children are increasingly vulnerable to these threats. This study aimed to assess levels of exposure and summarize the evidence for associations between exposures to environmental risk factors and adverse health outcomes in Mongolia, with a particular focus on children. A systematic review was conducted using the PubMed, EMBASE, Web of Science, Global Health Library, CINAHL, CABI, Scopus, and mongolmed.mn electronic databases up to April 2014 . A total of 59 studies meeting the predetermined criteria were included. Results indicate that the Mongolian population has significant exposure to outdoor and indoor air pollution, metals, environmental tobacco smoke, and other chemical toxins, and these risk factors have been linked to respiratory and cardiovascular diseases among adults and respiratory diseases and neurodevelopmental disorders among children. Well-designed epidemiological investigations in vulnerable populations especially in pregnant women and children are recommended.

Blood lead concentrations and children's behavioral and emotional problems: a cohort study

IMPORTANCE

The association between lead exposure and children's IQ has been well studied, but few studies have examined the effects of blood lead concentrations on children's behavior.

OBJECTIVE

To evaluate the association between blood lead concentrations and behavioral problems in a community sample of Chinese preschool children with a mean blood lead concentration of less than 10 µg/dL.

DESIGN, SETTING, AND PARTICIPANTS

A prospective cohort study was conducted at 4 preschools in Jintan, Jiangsu province of China. Participants included 1341 children aged 3 to 5 years.

EXPOSURES

Lead.

MAIN OUTCOMES AND MEASURES

Blood lead concentrations were measured in children aged 3 to 5 years. Behavioral problems were assessed using Chinese versions of the Child Behavior Checklist and Caregiver-Teacher Report Form when children were aged 6 years.

RESULTS

The mean (SD) blood lead concentration was 6.4 (2.6) µg/dL, with the 75th and 90th percentiles being 7.5 and 9.4 µg/dL, respectively. General linear modeling showed significant associations between blood lead concentrations and increased scores for teacher-reported behavioral problems. A 1-µg/dL increase in the blood lead concentration resulted in a 0.322 (95% CI, 0.058 to 0.587), 0.253 (95% CI, 0.016 to 0.500), and 0.303 (95% CI, 0.046 to 0.560) increase of teacher-reported behavior scores on emotional reactivity, anxiety problems, and pervasive developmental problems, respectively (P < .05), with adjustment for parental and child variables. Spline modeling showed that mean teacher-reported behavior scores increased with blood lead concentrations, particularly for older girls.

CONCLUSIONS AND RELEVANCE

Blood lead concentrations, even at a mean concentration of 6.4 µg/dL, were associated with increased risk of behavioral problems in Chinese preschool children, including internalizing and pervasive developmental problems. This association showed different patterns depending on age and sex. As such, continued monitoring of blood lead concentrations, as well as clinical assessments of mental behavior during regular pediatric visits, may be warranted.

Effect of acid rain pH on leaching behavior of cement stabilized lead-contaminated soil

Cement stabilization is a practical approach to remediate soils contaminated with high levels of lead. However, the potential for leaching of lead out of these stabilized soils under variable acid rain pH conditions is a major environmental concern. This study investigates the effects of acid rain on the leaching characteristics of cement stabilized lead contaminated soil under different pH conditions. Clean kaolin clay and the same soil spiked with 2% lead contamination are stabilized with cement contents of 12 and 18% and then cured for 28 days. The soil samples are then subjected to a series of accelerated leaching tests (or semi-dynamic leaching tests) using a simulated acid rain leachant prepared at pH 2.0, 4.0 or 7.0. The results show that the strongly acidic leachant (pH ∼2.0) significantly altered the leaching behavior of lead as well as calcium present in the soil. However, the differences in the leaching behavior of the soil when the leachant was mildly acidic (pH ∼4.0) and neutral (pH ∼7.0) prove to be minor. In addition, it is observed that the lead contamination and cement content levels can have a considerable impact on the leaching behavior of the soils. Overall, the leachability of lead and calcium is attributed to the stability of the hydration products and their consequent influence on the soil buffering capacity and structure.

An investigation of outpatient children's blood lead level in Wuhan China

Objective

Blood lead levels (BLLs) and possible influencing factors in children in Wuhan China were investigated in order to understand current lead pollution exposure and provide a scientific basis for prevention and policy making.

Materials and Methods

BLL data were collected from 15,536 out-patients in Wuhan Children Hospital in 2012 full year. All of them were under 18 years of age (Mean ± SD: 4.32±3.2, 64.4% boys). The BLLs were measured by an atomic absorption spectrometry (BH2100).

Results

The geometric mean of BLLs for all the subjects was 44.75 µg/L (95%CI: 44.46 µg/L – 45.05 µg/L), much lower than that reported in previous studies. The prevalence of the elevated BLLs (≥ 100 µg/L) in the children tested was 2% in 2012 and the prevalence of BLLs (≥ 50 µg/L) was 44%. Age and sex could be possible influencing factors for BLLs in the children (p<0.001). In addition, the BLLs in different seasons were different (p<0.001).

Conclusions

These results demonstrate that BLLs have significantly decreased in children in Wuhan during recent years. However, we should continuously pay attention to lead pollution and emphasize that prevention is much more important than treatment for controlling children's BLLs.

Association of blood lead level with neurological features in 972 children affected by an acute severe lead poisoning outbreak in Zamfara State, northern Nigeria

BACKGROUND

In 2010, Médecins Sans Frontières (MSF) investigated reports of high mortality in young children in Zamfara State, Nigeria, leading to confirmation of villages with widespread acute severe lead poisoning. In a retrospective analysis, we aimed to determine venous blood lead level (VBLL) thresholds and risk factors for encephalopathy using MSF programmatic data from the first year of the outbreak response.

METHODS AND FINDINGS

We included children aged ≤5 years with VBLL ≥45 µg/dL before any chelation and recorded neurological status. Odds ratios (OR) for neurological features were estimated; the final model was adjusted for age and baseline VBLL, using random effects for village of residence. 972 children met inclusion criteria: 885 (91%) had no neurological features; 34 (4%) had severe features; 47 (5%) had reported recent seizures; and six (1%) had other neurological abnormalities. The geometric mean VBLLs for all groups with neurological features were >100 µg/dL vs 65.9 µg/dL for those without neurological features. The adjusted OR for neurological features increased with increasing VBLL: from 2.75, 95%CI 1.27-5.98 (80-99.9 µg/dL) to 22.95, 95%CI 10.54-49.96 (≥120 µg/dL). Neurological features were associated with younger age (OR 4.77 [95% CI 2.50-9.11] for 1-<2 years and 2.69 [95%CI 1.15-6.26] for 2-<3 years, both vs 3-5 years). Severe neurological features were seen at VBLL <105 µg/dL only in those with malaria.

INTERPRETATION

Increasing VBLL (from ≥80 µg/dL) and age 1-<3 years were strongly associated with neurological features; in those tested for malaria, a positive test was also strongly associated. These factors will help clinicians managing children with lead poisoning in prioritising therapy and developing chelation protocols.

The Environment and Children's Health Care in Northwest China

Background

Industrialization in the northwest provinces of the People’s Republic of China is accelerating rapid increases in early life environmental exposures, yet no publications have assessed health care provider capacity to manage common hazards.

Methods

To assess provider attitudes and beliefs regarding the environment in children’s health, determine self-efficacy in managing concerns, and identify common approaches to managing patients with significant exposures or environmentally-mediated conditions, a two-page survey was administered to pediatricians, child care specialists, and nurses in five provinces (Gansu, Shaanxi, Xinjiang, Qinghai, and Ningxia). Descriptive and multivariable analyses assessed predictors of strong self-efficacy, beliefs or attitudes.

Results

960 surveys were completed with <5% refusal; 695 (72.3%) were valid for statistical analyses. The role of environment in health was rated highly (mean 4.35 on a 1-5 scale). Self-efficacy reported with managing lead, pesticide, air pollution, mercury, mold and polychlorinated biphenyl exposures were generally modest (2.22-2.52 mean). 95.4% reported patients affected with 11.9% reporting seeing >20 affected patients. Only 12.0% reported specific training in environmental history taking, and 12.0% reported owning a text on children’s environmental health. Geographic disparities were most prominent in multivariable analyses, with stronger beliefs in environmental causation yet lower self-efficacy in managing exposures in the northwestern-most province.

Conclusions

Health care providers in Northwest China have strong beliefs regarding the role of environment in children’s health, and frequently identify affected children. Few are trained in environmental history taking or rate self-efficacy highly in managing common hazards. Enhancing provider capacity has promise for improving children’s health in the region.

Simple whole-cell biodetection and bioremediation of heavy metals based on an engineered lead-specific operon

A lead-specific binding protein, PbrR, and promoter pbr from the lead resistance operon, pbr, of Cupriavidus metallidurans CH34 was incorporated into E. coli in conjunction with an engineered downstream RFP (red fluorescence protein), which allowed for highly sensitive and selective whole-cell detection of lead ions. The subsequent display of PbrR on the E. coli cell surface permitted selective adsorption of lead ions from solution containing various heavy metal ions. The surface-engineered E. coli bacteria effectively protected Arabidopsis thaliana seed germination from the toxicity of lead ions at high concentrations. Engineering the E. coli bacteria harboring these lead-specific elements from the pbr operon may potentially be a valuable general strategy for biodetection and bioremediation of toxic heavy metal ions in the environment.

Health risks from the exposure of children to As, Se, Pb and other heavy metals near the largest coking plant in China

Coking influences environmental quality and poses high risks to human health as large amounts of heavy metals and metalloids are emitted into the environment from coal during the coking process. Health risks depend heavily on multi-pathway and element-specific exposures, which have, unfortunately, been rarely studied. In this study, children's health risks and exposure levels to As, Se, and heavy metals (Pb, Cd, Cr, Ni, Co, Zn, Cu, Mn, V and Sb) in the water, soil, dust, air and locally produced food were studied based on field sampling and questionnaire-based surveys around the largest coking area in China. Human blood samples were collected and analyzed to indicate the exposure levels. The non-carcinogenic risks to children mainly resulted from Cr, Mn, Pb, As and Sb, the levels of which were 3 to 10 times higher than the acceptable levels (1.0×10(-6)). The carcinogenic risks to children were 30 to 200 times higher than the safe level (1.0×10(-6)-1.0×10(-4)), which could be attributed to Cr, As and Ni pollution. The estimated risks mainly came from the pathway involving the ingestion of locally produced food, accounting for more than 85% in total for most elements. For As, the food ingestion and air inhalation exposure pathways both contributed approximately 50%, respectively. The high risks in this study highlight the attention paid to the health of children who live in the vicinity of coking activities and the importance of site-specific multi-pathway health risk assessments and food safety to protect potentially exposed children.

Trace metals in atmospheric fine particles in one industrial urban city: spatial variations, sources, and health implications

Trace metals in PM2.5 were measured at one industrial site and one urban site during September, 2010 in Ji'nan, eastern China. Individual aerosol particles and PM2.5 samples were collected concurrently at both sites. Mass concentrations of eleven trace metals (i.e., Al, Ti, Cr, Mn, Fe, Ni, Cu, Zn, Sr, Ba, and Pb) and one metalloid (i.e., As) were measured by inductively coupled plasma atomic emission spectroscopy (ICP-AES). The result shows that mass concentrations of PM2.5 (130 microg/m3) and trace metals (4.03 microg/m3) at the industrial site were 1.3 times and 1.7 times higher than those at the urban site, respectively, indicating that industrial activities nearby the city can emit trace metals into the surrounding atmosphere. Fe concentrations were the highest among all the measured trace metals at both sites, with concentrations of 1.04 microg/m 3 at the urban site and 2.41 microg/m3 at the industrial site, respectively. In addition, Pb showed the highest enrichment factors at both sites, suggesting the emissions from anthropogenic activities existed around the city. Correlation coefficient analysis and principal component analysis revealed that Cu, Fe, Mn, Pb, and Zn were originated from vehicular traffic and industrial emissions at both sites; As, Cr, and part of Pb from coal-fired power plant; Ba and Ti from natural soil. Based on the transmission electron microscopy analysis, we found that most of the trace metals were internally mixed with secondary sulfate/organic particles. These internally mixed trace metals in the urban air may have different toxic abilities compared with externally mixed trace metals.

Human biological monitoring of suspected endocrine-disrupting compounds

Endocrine-disrupting compounds are exogenous agents that interfere with the natural hormones of the body. Human biological monitoring is a powerful method for monitoring exposure to endocrine disrupting compounds. In this review, we describe human biological monitoring systems for different groups of endocrine disrupting compounds, polychlorinated biphenyls, brominated flame retardants, phthalates, alkylphenols, pesticides, metals, perfluronated compounds, parabens, ultraviolet filters, and organic solvents. The aspects discussed are origin to exposure, metabolism, matrices to analyse, analytical determination methods, determinants, and time trends.