The Risk Factors of Child Lead Poisoning in China: A Meta-Analysis

The feasibility of K XRF bone lead measurements in mice assessed using 3D-printed phantoms

This article describes the development of a system forin vivomeasurements of lead body burden in mice using109Cd K x-ray fluorescence (XRF). This K XRF system could facilitate early-stage studies on interventions that ameliorate or reverse organ tissue damage from lead poisoning by reducing animal numbers through a cross-sectional study approach. A novel mouse phantom was developed based on a mouse atlas and 3D-printed using PLA plastic with plaster of Paris 'bone' inserts. PLA plastic was found to be a good surrogate for soft tissue in XRF measurements and the phantoms were found to be good models of mice. As expected, lead detection limits varied with mouse size, mouse orientation, and mouse position with respect to the source and detector. The work suggests that detection limits of 10 to 20μg Pb per g bone mineral may be possible for a 2 to 3 hour XRF measurement in a single animal, an adequate limit for some pre-clinical studies. The109Cd K XRF mouse measurement system was also modeled using the Monte Carlo code MCNP. The combination of experiment and modeling found that contrary to expectation, accurate measurements of lead levels in mice required calibration using mouse-specific calibration standards due to the coherent scatter peak normalization failing when small animals are measured. MCNP modeling determined that this was because the coherent scatter signal from soft tissue, which until now has been assumed negligible, becomes significant when compared to the coherent scatter signal in bone in small animals. This may have implications for some human measurements. This work suggests that109Cd K x-ray fluorescence measurements of lead body burden are precise enough to make the system feasible for small animals if appropriately calibrated. Further work to validate the technology's measurement accuracy and performancein vivowill be required.

Comparison of Blood Lead Levels in Children and Adolescents with and without Functional Abdominal Pain

Background

Functional abdominal pain is a health concern with chronic abdominal discomfort without clear etiology. Several etiologic factors are raised in this regard, one related to environmental factors. This study aimed to compare blood lead levels between children and adolescents with and without functional abdominal pain.

Materials and Methods

This case-control study was performed in 2019-2020 in Isfahan, Iran. The sample size was calculated as 70 cases and an equal number of controls. Cases were children and adolescents with functional gastrointestinal disorder (FGID), and controls were grouped age- and sex-matched. Controls were randomly selected from those referred for routine health screening. Both groups obtained blood lead, iron, and calcium levels. All participants completed the FFQ Food Consumption and Environmental Pollutants Questionnaire.

Results

Participants were 139 children (68 cases and 71 controls). The mean (SD) age was 9.40 (3.91) years in the FGID group and 8.79 (3.46) years in the controls (P = 0.330). The mean (SD) blood lead level was not significantly different between the FGID group and the controls (3.98 ± 2.56 vs 3.81 ± 1.96 μg/dl, respectively, P = 0.670). We found that 55.3% of children with high lead levels had FGID, while 44.4% of children with lower lead levels had FGID, but the difference was not statistically significant (P = 0.33).

Conclusion

We found that the lead level was higher in patients with FGID than in the controls; however, this difference was not significantly different. This might be because of elevated lead levels in both groups. Future ecological studies with a large sample size are necessary in this regard.

Carcinogenic and non-carcinogenic risk assessment of consuming metal-laden wild mushrooms in Nigeria: Analyses from field based and systematic review studies

This study investigated the potential health risk associated with the consumption of metal-laden mushrooms in Nigeria. Concentrations of Pb, Cd, Cr, Cu, Ni, Zn and Al in wild mushrooms collected from the Nigerian environment were measured using atomic absorption spectrometer. Also, systematic analysis of articles on metal accumulation in mushrooms from Nigeria were obtained from scientific databases. Using hazard model indices, the metal concentration in mushrooms were evaluated for their potential carcinogenic and non-carcinogenic health risk when consumed by adults and children. Zn and Cd, respectively, had the highest and lowest mean concentrations (mg kg-1) in the analysed mushrooms from the field study, while Fe and Co, respectively, had the highest and lowest mean concentrations (mg kg-1) in the systematically reviewed articles. In the field study, the percentage distribution of THQ of the heavy metals greater than 1 was 0% and 42.85% for adults and children respectively. While for the systematic study, 30% and 50% of the heavy metals for adults and children respectively exceeded the limit of 1. The hazard indices obtained from both the systematic and field studies for both age groups were all >1, indicating significant health risk. The findings from both the systematic and field studies revealed that consuming metal-laden mushrooms by adults and children increases the carcinogenic risk to Cd, Cr, and Ni since they exceeded the acceptable limit of 1E-04 stated by USEPA guideline. Based on the findings from the systematic and field studies, it suggests that consuming mushrooms collected from metal polluted substrates increases carcinogenic and non-carcinogenic health risk among Nigerians.

Low level lead exposure in early childhood and parental education on adolescent IQ and working memory: a cohort study

BACKGROUND

The independent effect of lead exposure and parental education on children's neurocognition is well-documented. However, few studies have examined the combined effect of childhood lead exposure and parental education on adolescent neurocognition, especially in China.

OBJECTIVE

Examine both the combined and interactive effect of childhood blood lead levels (BLLs) and parental education on early adolescent neurocognition.

METHODS

417 children from a longitudinal cohort study in Jintan, China had BLLs measured at 3-5 years and 12 years, parental education levels assessed at 3-5 years, and neurocognitive outcomes tested at 12 years.

RESULTS

BLLs at 3-5 years were inversely associated with adolescent IQ (β -0.55 95% CI: -0.97, -0.13) but not working memory (β -0.06 95% CI: -0.23, 0.11) and parental education was positively associated with adolescent IQ (β 0.68 95% CI: 0.19, 1.17) and working memory (β 0.24 95% CI: 0.04, 0.44). BLLs and parental education evidenced combined effects on neurocognition, where children with higher BLLs and lower fathers' education had mean IQ scores 7.84 (95% CI: -13.15, -2.53) points lower than children with lower BLLs and higher fathers' education. There were significant associations between parental education and working memory, however, not with BLLs. The interaction between mother and father high school education and BLLs was insignificant for effects on IQ and working memory.

SIGNIFICANCE

Childhood lead exposure and parental education levels have a combined and long-term impact on IQ, evidence that may partially explain disparities in lead exposure associated outcomes and highlight those children at greatest risk for neurocognitive deficits.

IMPACT STATEMENT

Children continue to be exposed to low-levels of environmental lead in China and globally, warranting examination of the impact of such exposures. This paper demonstrates that even relatively low-level lead exposure in early childhood significantly influences adolescent neurocognitive functioning. Furthermore, co-existing social determinant of health-related variables, measured here as parental education, have a combined impact on neurocognition. These results highlight children at greater risk for neurocognitive deficits and demonstrate the need to examine the influence of lead exposure within the broader socio- ecological environment, as these factors work in tandem to influence longer-term neurocognitive outcomes.

Iron Chelators in Treatment of Iron Overload

Patients suffering from iron overload can experience serious complications. In such patients, various organs, such as endocrine glands and liver, can be damaged. Although iron is a crucial element for life, iron overload can be potentially toxic for human cells due to its role in generating free radicals. In the past few decades, there has been a major improvement in the survival of patients who suffer from iron overload due to the application of iron chelation therapy in clinical practice. In clinical use, deferoxamine, deferiprone, and deferasirox are the three United States Food and Drug Administration-approved iron chelators. Each of these iron chelators is well known for the treatment of iron overload in various clinical conditions. Based on several up-to-date studies, this study explained iron overload and its clinical symptoms, introduced each of the above-mentioned iron chelators, and evaluated their advantages and disadvantages with an emphasis on combination therapy, which in recent studies seems a promising approach. In numerous clinical conditions, due to the lack of accurate indicators, choosing a standard approach for iron chelation therapy can be difficult; therefore, further studies on the issue are still required. This study aimed to introduce each of these iron chelators, combination therapy, usage doses, specific clinical applications, and their advantages, toxicity, and side effects.

Assessment of Urinary Lead (Pb) and Essential Trace Elements in Autism Spectrum Disorder: a Case-Control Study Among Preschool Children in Malaysia

Lead (Pb) is a heavy metal which is abundant in the environment and known to cause neurotoxicity in children even at minute concentration. However, the trace elements calcium (Ca), magnesium (Mg), zinc (Zn) and iron (Fe) are essential to children due to its protective effect on neurodevelopment. The primary objective of this study was to assess the role of Pb and trace elements in the development of autism spectrum disorder (ASD) among preschool children. A total of 81 ASD children and 74 typically developed (TD) children aged between 3 and 6 years participated in the study. Self-administered online questionnaires were completed by the parents. A first-morning urine sample was collected in a sterile polyethene urine container and assayed for Pb, Ca, Mg, Zn and Fe using an inductively coupled plasma mass spectrometry (ICP-MS). Comparisons between groups revealed that the urinary Pb, Mg, Zn and Fe levels in ASD children were significantly lower than TD children. The odds of ASD reduced significantly by 5.0% and 23.0% with an increment of every 1.0 μg/dL urinary Zn and Fe, respectively. Post interaction analysis showed that the odds of ASD reduced significantly by 11.0% and 0.1% with an increment of every 1.0 μg/dL urinary Zn and Pb, respectively. A significantly lower urinary Pb level in ASD children than TD children may be due to their poor detoxifying mechanism. Also, the significantly lower urinary Zn and Fe levels in ASD children may augment the neurotoxic effect of Pb.

Advances in the Functional Nucleic Acid Biosensors for Detection of Lead Ions

Lead ions (Pb²⁺) are destructive to the natural environment and public health, so the efficient detection of Pb²⁺ is particularly important. Although the instrumental analysis methods have high accuracy, they require high cost and precise operation, which limits their wide application. Therefore, many strategies have been extensively studied for detecting Pb²⁺ by biosensors. Functional nucleic acids have become an efficient tool in this field. This review focuses on the recent biosensors of detecting Pb²⁺ based on functional nucleic acids from 2010 to 2020, in which DNAzyme, DNA G-quadruplex and aptamer will be introduced. The biosensors are divided into three categories that colorimetric, fluorometric and electrochemical biosensors according to the different reported signals. The action mechanism and detection effect of each biosensor are explained. Finally, the present situation of nucleic acid biosensor for the detection of Pb²⁺ is summarized and the future research direction is prospected.

Challenges in diagnosing lead poisoning: A review of occupationally and nonoccupationally exposed cases reported in India

Lead is a nonessential metal which enters the body through various means and is considered as one of the most common health toxins. Several cases of lead poisoning are reported as a result of inhalation or ingestion of lead in employees working as painters, smelters, electric accumulator manufacturers, compositors, auto mechanics, and miners. In addition to occupational lead exposure, several cases of lead poisoning are reported in the general population through various sources and pathways. Innumerable signs and symptoms of lead poisoning observed are subtle and depend on the extent and duration of exposure. The objective of this review article is to discuss occupationally and nonoccupationally exposed lead poisoning cases reported in India and the associated symptoms, mode of therapy, and environmental intervention used in managing these cases. Lead poisoning cases cannot be identified at an early stage as the symptoms are very general and mimic that of other disorders, and patients might receive only symptomatic treatment. Knowledge about the various symptoms and potential sources is of utmost importance. Medical practitioners when confronted with patients experiencing signs and symptoms as discussed in this article can speculate the possibility of lead poisoning, which could lead to early diagnosis and its management.

Experimental simulation of somatic and germ cell genotoxicity in male Mus musculus fed extracts of lead contaminated Pleurotus ostreatus (white rot fungi)

Exposure to lead (Pb) is a major risk factor in reproductive toxicity, somatic, and germ cell genotoxicity. Exposure via deteriorating Pb paints and contaminated air, soil, and water had been the primary routes. However, with increasing reports of Pb accumulation in mushrooms and other food items may increase the etiology of Pb poisoning. The study herein investigated somatic genotoxicity and reproductive abnormalities in mice fed extracts of Pb-contaminated Pleurotus ostreatus. Male mice were fed aqueous extracts of P. ostreatus cultivated in 0, 10, 20, 100, 200, 500, and 1000 mg/L of Pb-contaminated rice straw for 35 days. Testes were analyzed for Pb accumulation, histopathology and relative weight gain, caudal epididymis for abnormal sperm morphology, and bone marrow for micronucleus test. Concentration-related significant increase in Pb accumulation was observed in P. ostreatus and testes of exposed mice. Decrease testicular weight, congestion of blood vessels, necrosis, and disorganization of the seminiferous tubules were observed in treated mice. In addition, fold increase of 2.78, 3.39, 6.67, 7.21, 9.63, and 9.70 in abnormal sperm morphology in accordance with the Pb concentrations respectively, confirmed reproductive toxicity. Significant increase in micronucleated polychromatic (PCE) and normochromatic (NCE) erythrocytes and concentration-related decrease PCE-NCE ratio in the bone marrow of treated mice suggest genome instability. Pb-contaminated P. ostreatus increased somatic and germ cell genotoxicity in mice. This may predispose the mice to genetic related syndromes and reproductive syndromes. It further suggests caution in the consumption of metal laden wild mushrooms and crop plants.

Removal of lead ions from water using thiophene-functionalized metal-organic frameworks

Heavy metal ion contamination in water is a hazard to all life. The removal of such ions from aqueous media by porous metal-organic frameworks (MOFs) is a growing field. Herein we report the use of thiophene containing MOFs, notably DUT-67, for the removal of Pb2+ ions from water under both batch and flow conditions with a max loading of 98.5 mg Pb2+ per g MOF. Solution-phase 207Pb NMR spectroscopy and an observed decrease in adsorption with non-thiophene containing systems support a mechanism of adsorption via a putative 6π-η5-thiophene-Pb2+ coordination.

Childhood lead poisoning in Gaza Strip, the Palestinian Authority

PURPOSE

To assess lead poisoning among a pediatric population in Gaza Strip, the Palestinian Authority.

METHODS

A total of 1705 questionnaires and blood samples were collected from children aged 2-6 years, by the finger stick capillary procedure, for the assessment of blood lead level (BLL), using the LeadCare kits. The samples were collected from children living close to lead processing units (hotspots) and far 100-500 m away (general population). Management of elevated BLL was achieved by gavage of chelating agent d-penicillamine at a dose of 30 mg kg^-1 body weight/day for two weeks for children having BLL above 20 μg/dl. Data were statistically analyzed using SPSS computer program version 22.

RESULTS

Distribution of children in Gaza Strip by sampling process illustrated those 326 children (19.1%) living in lead processing units (hot spots) and 1379 children (80.9%) from location far away 100-500 m from host spot (general population). The mean BLL was 10.4 μg/dl. A total of 440 children (25.8%) were found to be having BLL ≥ 10 μg/dl while 1265 children (74.2%) have BLL < 10 μg/dl. BLL < 10 μg/dl was taken as a cut point due to CDC standards. The prevalence of BLL in hotspot areas in children who were exposed to lead and have BLL ≥ 10 μg/dl was 95.7% while in general population it was 9.3%. The difference between the study population was statistically significant (p < 0.01). Statistical significant differences between the study populations were found among several independent variables of risk factors such as household location and exposure sources, and occupational exposure. Gavage of d-penicillamine significantly reduced BLL to the acceptable level (BLL < 10 μg/dl).

CONCLUSIONS

Childhood lead poisoning accounts for a substantial burden in Gaza Strip. Hotspots of lead-related industries are the high risk areas that contributing to high BLLs in children. d-Penicillamine was effective in the treatment of lead poisoning among children. Health education and treatment campaigns should be designed to minimize or prevent childhood lead poisoning in Gaza Strip.

Use of a Survey to Assess the Environmental Exposure and Family Perception to Lead in Children (<6 Years) in Four Valley Cities, Northwestern China

With the growth of industry, the extensive use of lead, and urban expansion in Northwestern Valley Cities (NVC) China, there is probable reason for presuming an increasing risk of lead exposure. However, little is known about the lead exposure of children less than 6 years old in NVC. As a first investigation, this study uses a survey to systematically determine the influences of various risk factors within the family environment, parents' background, children's behavior, mother's behavior during pregnancy, and parental perception about children's blood lead (CBL). A total of 596 families were recruited from the general population in Urumqi, Lanzhou, Xining and Yan'an. Parents, and their children (<6 years old), were asked about the environment and behaviors which could possibly relate with lead exposure. The results indicated that in the typical NVC of China, children's environment and behavior, parents' education level, and mother's pregnancy behavior, were associated with potential CBL. It was noted that not all parents in NVC China recognized the importance of children's lead exposure. Therefore, children's health care and medical screening campaigns need to be designed to improve family's fundamental knowledge of lead hazards, associated health effects, and prevention in the NVC of China.

Unintentional Poisoning in China, 1990 to 2015: The Global Burden of Disease Study 2015

OBJECTIVES

To estimate the unintentional poisoning burden and risk factors in China from 1990 to 2015.

METHODS

We extracted data from the Global Burden of Disease Study 2015 to compare mortality, prevalence, disability-adjusted life years (DALYs), years of life lost, years lived with a disability, and risk factors of unintentional poisoning in China. We determined the median of the percent change and 95% uncertainty interval for the period between 1990 and 2015.

RESULTS

The age-standardized unintentional poisoning death rate decreased by 61.8% from 1990 (4.1 per 100 000) to 2015 (1.6 per 100 000). The age-standardized prevalence decreased from 1990 (87.9 per 100 000) to 2010 (39.0 per 100 000), but rebounded in 2015 (42.6 per 100 000). All risk factors combined accounted for 14.9% of unintentional poisoning DALYs in 2015. The leading risk factors for unintentional poisoning DALYs were alcohol and drug use and occupational risks.

CONCLUSIONS

China has made substantial progress in reducing the mortality attributable to unintentional poisoning, but the prevalence and absolute number of patients has been increasing again since 2010. The growing contribution from alcohol and drug use requires increased attention.

Blood Lead Levels and Risk Factors among Preschool Children in a Lead Polluted Area in Taizhou, China

Objective. To determine the blood lead levels and identify related risk factors among preschool children in a lead polluted area (Taizhou, China) and provide theoretical support for prevention of lead pollution. Methods. A stratified-clustered-random sampling method was used to determine the survey sample. Blood lead levels were determined by the tungsten atomizer absorption spectrophotometer. Results. A total of 2,018 subjects (average age of 59 months; 1,087 boys and 931 girls) were included. The arithmetic mean, geometric mean, and median blood lead levels of the preschool children were 56.4 μg/L, 48.9 μg/L, and 46 μg/L. A total of 8.8% children had blood lead levels >100 μg/L and 43.9% had blood lead levels >50 μg/L. Mother's education level, father's occupation, decorative tableware, exposure to makeup, and the residential floor were all risk factors for elevated blood lead levels (odds ratios of 1.42, 1.21, 1.11, 1.19, and 1.27, resp.), while hand washing before eating food was a protective factor (odds ratio of 0.88). Conclusions. The blood lead levels of preschool children in Taizhou were higher than in other areas in China and in developed countries. Therefore, policies ensuring lead-based industries are not placed in close proximity to residential areas are required.

A Review on Iron Chelators in Treatment of Iron Overload Syndromes

Iron chelation therapy is used to reduce iron overload development due to its deposition in various organs such as liver and heart after regular transfusion. In this review, different iron chelators implicated in treatment of iron overload in various clinical conditions have been evaluated using more up-to-date studies focusing on these therapeutic agents. Deferoxamine, Deferiprone and Deferasirox are the most important specific US FDA-approved iron chelators. Each of these chelators has their own advantages and disadvantages, various target diseases, levels of deposited iron and clinical symptoms of the afflicted patients which may affect their selection as the best modality. Taken together, in many clinical disorders, choosing a standard chelator does not have an accurate index which requires further clarifications. The aim of this review is to introduce and compare the different iron chelators regarding their advantages and disadvantages, usage dose and specific applications.

Editorial: Lead Risk Assessment and Health Effects

In 1980, Clair C. Patterson stated: “Sometime in the near future it probably will be shown that the older urban areas of the United States have been rendered more or less uninhabitable by the millions of tons of poisonous industrial lead residues that have accumulated in cities during the past century”. We live in the near future about which this quote expressed concern. This special volume of 19 papers explores the status of scientific evidence regarding Dr. Patterson’s statement on the habitability of the environments of communities. Authors from 10 countries describe a variety of lead issues in the context of large and small communities, smelter sites, lead industries, lead-based painted houses, and vehicle fuel treated with lead additives dispersed by traffic. These articles represent the microcosm of the larger health issues associated with lead. The challenges of lead risk require a concerted global action for primary prevention.