Lead Toxicity in Children: Health Effects, Policies and Recommendations

Lead is a dangerous element that exists naturally in the Earth's crust. Any kind of lead causes a detrimental response in the human body. It is discharged into the environment during the manufacturing of batteries, foundries, ammunition, lead paint, water pipes, and other manufactured goods. It can enter the body through a variety of pathways, including those in the air, water, soil, food, and dust. Concern is raised since there is no amount of lead that is safe for the human body. The problem persists despite several prevention measures that the state and the federal governments have put in place. This review assesses the effects of lead exposure on children as well as suggested solutions to the issue.

Moringa oleifera leaf ethanol extract ameliorates lead-induced hepato-nephrotoxicity in rabbits

Objective: To evaluate the effect of Moringa oleifera leaf ethanol extract as an adjunct treatment on lead acetate induced hepato-nephrotoxicity in rabbits. Methods: Thirty-six male New Zealand White rabbits were assigned into two main groups. The first group (14 rabbits) served as normal control. The secondgroup (22 rabbits) was administered orally with lead acetate at a dose of 40 mg/kg/day, 5 days/week for 8 weeks. At the 4th and the 8th week of treatment, 6 animals (3 animals at each period) of the second group were sacrificed while the remaining animals (16 rabbits) were assigned randomly into 2 subgroups (8 rabbits each): treated and non-treated. The first subgroup was orally given 1 mL phosphate-buffered saline for further 4 weeks while the second subgroup was administered orally with Moringa oleifera leaf ethanol extract at a dose of 400 mg/kg/day for the same period. Blood samples were collected to determine hematological and serum biochemical indices. Tissue specimens were collected from the liver and kidney for evaluation of the oxidant/antioxidant markers and for histopathological examinations. Results: Lead acetate exposure decreased the mean body weight gain, hematocrit, hemoglobin, mean corpuscular volume, and lymphocytes count. Moreover, it markedly increased counts of monocytes and platelets, serum enzyme activity, levels of creatinine, total cholesterol, triglycerides, and low-density lipoprotein cholesterol. Malondialdehyde level was markedly increased while the reduced glutathione content was significantly decreased in liver tissue of lead intoxicated-rabbits. Histopathological alterations were also noticed in the liver and kidney of lead intoxicated rabbits. Moringa oleifera leaf ethanol extract significantly improved hematological and serum biochemical parameters and histopathological structure of the liver and kidney. Conclusions: Moringa oleifera leaf ethanol extract ameliorates hemato-biochemical and histopathological alterations caused by lead acetate and improveshepatic and renal functions.

Moringa oleifera leaf ethanol extract ameliorates lead-induced hepato-nephrotoxicity in rabbits

Objective: To evaluate the effect of Moringa oleifera leaf ethanol extract as an adjunct treatment on lead acetate induced hepato-nephrotoxicity in rabbits.Methods: Thirty-six male New Zealand White rabbits were assigned into two main groups. The first group (14 rabbits) served as normal control. The second group (22 rabbits) was administered orally with lead acetate at a dose of 40 mg/kg/day, 5 days/week for 8 weeks. At the 4th and the 8th week of treatment, 6 animals (3 animals at each period) of the second group were sacrificed while the remaining animals (16 rabbits) were assigned randomly into 2 subgroups (8 rabbits each): treated and non-treated. The first subgroup was orally given 1 mL phosphate-buffered saline for further 4 weeks while the second subgroup was administered orally with Moringa oleifera leaf ethanol extract at a dose of 400 mg/kg/day for the same period. Blood samples were collected to determine hematological and serum biochemical indices. Tissue specimens were collected from the liver and kidney for evaluation of the oxidant/antioxidant markers and for histopathological examinations. Results: Lead acetate exposure decreased the mean body weight gain, hematocrit, hemoglobin, mean corpuscular volume, and lymphocytes count. Moreover, it markedly increased counts of monocytes and platelets, serum enzyme activity, levels of creatinine, total cholesterol, triglycerides, and low-density lipoprotein cholesterol. Malondialdehyde level was markedly increased while the reduced glutathione content was significantly decreased in liver tissue of lead intoxicated-rabbits. Histopathological alterations were also noticed in the liver and kidney of lead intoxicated rabbits. Moringa oleifera leaf ethanol extract significantly improved hematological and serum biochemical parameters and histopathological structure of the liver and kidney. Conclusions: Moringa oleifera leaf ethanol extract ameliorates hemato-biochemical and histopathological alterations caused by lead acetate and improves hepatic and renal functions.

Reporte nacional de niveles de plomo en sangre y uso de barro vidriado en población infantil vulnerable / National report of blood lead levels and lead-glazed ceramics use in vulnerable children

Resumen: Objetivo: Estimar la prevalencia de niveles elevados (≥5.0μg/dL) de plomo en sangre (PbS) y su asociación con el uso de loza de barro vidriado con plomo (LBVPb). Material y métodos: En 2018 se midió PbS capilar en una muestra representativa de niños de 1 a 4 años de edad residentes en localidades de México menores de 100 000 habitantes (Ensanut 100k). Se indagó sobre uso de LBVPb para consumo de alimentos. Para estimar su asociación con PbS, se generaron modelos logit multinomial estratificados por región. Resultados: La prevalencia de niveles elevados de PbS fue de 21.8%. En las regiones Norte, Centro y Sur las prevalencias fueron 9.8, 20.7 y 25.8%, respectivamente. La asociación con uso y frecuencia de LBVPb fue altamente significativa y diferencial por región. Conclusiones: La exposición a plomo permanece como un problema de salud pública en México, particularmente en el Centro y Sur, y está fuertemente asociada con el uso de LBVPb.

Abstract: Objective: To estimate the prevalence of elevated (≥5.0μg / dL) blood lead levels (BLL) and its association with the use of lead glazed ceramics (LGC). Materials and methods: In 2018, we measured capillary BLL in a representative sample of children 1 to 4 years old residing in Mexican localities under 100 000 inhabitants (Ensanut 100k). We inquired about use of LGC for food preparation and consumption. To estimate its association with BLL, multinomial logit models stratified by region were generated. Results: The prevalence of elevated BLL levels was 21.8%. For the North, Central and South regions, the prevalence were 9.8, 20.7 and 25.8%, respectively. The association with use and frequency of LGC was highly significant and differential by region. Conclusions: Lead exposure remains a public health problem in Mexico, particularly in the Central and South regions, and is strongly associated with the use of LGC.

Accuracy of lead risk assessment questionnaire in predicting elevated blood lead levels in children

Background: Lead toxicity in children is a serious problem affecting their neurodevelopment. Although CDC mandates screening for lead toxicity regularly in children, India doesn't have any lead related public health program in place. In resource limited India a prescreening lead risk assessment questionnaire will be more economical than universal screening for blood lead levels (BLL). Authors aim to evaluate the accuracy of a validated modified CDC lead risk assessment questionnaire in predicting elevated BLL.Methods: Authors conducted an explorative cross-sectional study from July to August 2017 in 340 children aged 6 months to 6 years. A standardized self-administered questionnaire modified from CDC lead risk assessment questionnaire was administered in the children. Also, BLL were measured in all study subjects using lead care II analyser. Data from questionnaire were compared with BLL to test the accuracy of questionnaire.Results: Blood lead levels was high (>5ug/dl) in 57.9% of study subjects especially in children between 24-35 months. Employment in battery manufacturing companies (P=0.0001), usage of cosmetics (P=0.019), parental smoking history (P=0.001), involvement in painting, arts (P=0.0001) and malnourished children (P=0.018) were the risk factors associated with undesirable BLL. The modified questionnaire had a sensitivity of 87.9% and specificity of 66.7% for detecting elevated BLL.Conclusions: The modified CDC lead risk assessment questionnaire is a sensitive tool in identifying high risk cases of lead toxicity in children.

Nutrition-pollution interaction: An emerging research area

The impact of environmental pollution, especially chronic low exposures of heavy metals (Pb, Cd, Hg, As, Cr, etc.) on nutritional status and health of human and livestock, has become a cause of concern. It is established that malnutrition inhibits enzyme system, alters neurotransmitter levels, degenerate myelin, glial and neural elements, lowering of IQ scores as well as impairment of fine and gross motor coordination. Chronic low-level exposure to heavy metals also results in similar type of deformities at sub-clinical level. However, additive impact of undernutrition and adverse effects of heavy metal exposure is emerging as a serious threat to health in developing countries. High blood Pb/Cd levels and low nutrient levels cause subclinical damage of organ system such as haemopoietic, renal, nervous systems in neonates, children, post-partum women, and occupationally exposed population. This could be due to chronic low-level heavy metal exposures and vis-à-vis interaction between pollutants and nutrients. Our studies are focused on the utility of biomarkers for early subclinical detection of haemopoietic and rental toxicity. Lead exposure from non-conventional sources such as toys, pet/glass bottles, etc. suggest long-term investigation. The present review compiles result of studies conducted in this area highlighting the importance of pollution-nutrition interaction. This may facilitate policymakers on developing the strategies to counter the heavy metal exposure of humans/livestock and their consequences.

Factors Associated With Elevated Blood Lead Levels in Children

Objectives: To determine the prevalence and correlates of elevated blood lead level inchildren (6-144 months) of Aligarh. Methods: A hospital-based cross-sectional study wasconducted. Venous blood was obtained for lead estimation and a structured questionnairewas filled. Results: A total of 260 children were enrolled. The prevalence of elevated bloodlead level was 44.2%, seen mostly in children below 5 years of age. Old and deteriorating wallpaints at home was found to be significantly associated with elevated levels. Conclusions:Lead-based house paints are potential source of lead exposure. Meticulous renovation andpainting of the walls with safe paints is desirable

Mollusc C-reactive protein crosses species barrier and reverses hepatotoxicity of lead in rodent models.

Achatina fulica C-reactive protein (ACRP) reversed the toxic effects of lead nitrate both in vivo in mice and in vitro in rat hepatocytes restoring the basal level of cell viability, lipid peroxidation, reduced glutathione and superoxides. Cytotoxicity was also significantly ameliorated in rat hepatocytes by in vitro pre-treatments with individual subunits (60, 62, 90 and 110 kDa) of ACRP. Annexin V-Cy3/CFDA dual staining showed significant reduction in the number of apoptotic hepatocytes pre-treated with ACRP. ACRP induced restoration of mitochondrial membrane potential was remarkable. ACRP pre-treatment prevented Pb-induced apoptosis mediated by caspase activation. The antagonistic effect of ACRP may be due to scavenging of reactive oxygen species which maintained the homeostasis of cellular redox potential as well as reduced glutathione status. The results suggest that ACRP crosses the species barrier and it may be utilized as a viable exogenous agent of cytoprotection against heavy metal related toxicity.

Intoxicación por plomo: diagnósticodiferencial de dolor abdominal crónico. Reporte de caso y revisión de tema / Lead Poisoning: differential diagnosis of chronic abdominal pain. Case report and review

En este artículo se presenta el caso de un paciente con intoxicación crónica por plomo, cuya principal manifestación clínica fue dolor abdominal. Esta es una intoxicación quegeneralmente se presenta en pacientes que están en contacto laboral con este metal. En este artículo se revisan las manifestaciones clínicas más frecuentes y el manejo de estapatología, ya que de no identificarse y tratarse de forma oportuna, cursa con una alta morbimortalidad...

This article presents a case of chronic lead poisoning, which principal manifestation was abdominal pain. This usually occurs in patient who works with the metal. We reviewed the most frequent clinical manifestation and management. If is untreated thispoisoning has a high morbidity and mortality...

Growth, photosynthetic activity and oxidative stress in wheat (Triticum aestivum) after exposure of lead to soil.

The present study was conducted to assess quantitative information about lead (Pb) contamination in soil on the growth and physiology of wheat. Solutions with three different concentrations of Pb as [Pb(NO3)2 at 500, 1000 and 2500 >M] were incorporated into the soil to achieve Pb-stressed conditions in comparison to unstressed, water treated, control variant. Wheat growth measured in terms of root length, shoot length and dry weight exhibited a significant decline with increasing Pb concentrations in the soil. Root and shoot length and seedling weight declined in the range of ~23–51, ~17–44, and ~21–44% in response to 500 to 2500 >M Pb. In addition, there was a significant reduction in the levels of photosynthetic pigments-chlorophyll a (16-66%) and b (10-24%) and total chlorophyll content (by 14-39%) in plants growing in Pb-contaminated soil. It indicated a negative effect on photosynthetic activity in wheat and was confirmed by reduced photochemical efficiency of PSII (Fv/Fm) in the range of ~ 3-37% in response to 500 to 2500 >M Pb. The reduction in wheat growth in Pb-contaminated soil was accompanied by induction of oxidative stress as indicated by enhanced lipid peroxidation in terms of malondialdehyde (MDA) content (by 18-40%) and hydrogen peroxide (H2O2) content (by 34-123%) and alterations in the activity of enzymes, superoxide dismutases (SOD) and guaiacol peroxidases (GPX) in wheat roots. The study concludes that Pb in soil inhibits growth and phototsynthetic activity in wheat through induction of oxidative stress.

Influence of lead on growth and nutrient accumulation in canola (Brassica napus L.) cultivars.

Canola (Brassica napus L.) is commonly used as a hyper-accumulator for phytoextraction of heavy metals from soil and water. Like many other heavy metals, lead (Pb) contaminates soil, water and air and thus it is a great problem. This study was conducted to investigate toxic effects of Pb on growth and nutrient uptake in four canola cultivars. Each of four cultivars of canola (Con-II, Con-III, Legend and Shiralee) was subjected to four levels of Pb (0, 30, 60 and 90 mg Pb kg-1 of soil) from lead chloride [PbCl2]. Due to Pb toxicity, plant growth was adversely affected and relatively a severe reduction in root biomass (45.7%) was recorded. The Pb accumulation increased both in shoot and root, the highest being in root. The uptake of different nutrients, i.e., N, P, K, Ca, Mg, Zn, Cu and Mn was reduced (38.4, 32.8, 33.1, 49.6, 7.78, 52.0, 42.6 and 45.9%, respectively) in the shoots and that of N, Fe, Zn, and Cu in the roots (48.5, 33.2, 24.3 and 44.8%, respectively) of all canola cultivars. The root K, P, Zn and Mn and shoot P, Mg and Fe contents were less affected, the concentration of Pb, Ca and Mg in roots of all cultivars. Among canola cultivars Con-II and Con- III performed better than Legend and Shiralee in terms of growth (26.03%) and nutrient accumulation. Overall, plant growth and nutrient accumulation in the canola cultivars was hampered due to the presence of Pb.

Toxicidade do chumbo e sua substituição em ligas estanho-chumbo / Lead toxicity and its replacement in tin-lead alloys

Objetivo - Neste trabalho, avaliam-se possíveis metais substitutos do chumbo em ligas Sn-Pb. Essa substituição é necessária pelos riscos de natureza ambiental e de saúde pública advindos da toxicidade do chumbo. Método - O método utilizado baseou-se na análise e no modelamento matemático do perfil da gota metálica obtido no ensaio da gota séssil. Resultados e Conclusões - São frequentes as propostas de substituição do chumbo em ligas metálicas, em função do seu potencial nocivo ao ambiente e à saúde pública, por prata, índio ou bismuto.No entanto, essas propostas podem não atender às propriedades físicas e químicas necessárias, comprometer a qualidade do produto final e apresentar elevado custo. A taxa de reciclagem pode ser fator decisivo no controle da relação entre as soldas com chumbo e as isentas de chumbo.

Objective - In this paper, possible replacements for lead in Sn-Pb alloys are evaluated. This replacement is required due the environmental and public health risks arising from lead toxicity. Method - The used method was based on analysis and modeling the metal drop profile obtained on sessile droplet test. Results and Conclusions - There are frequent proposals for the replacement of lead alloys in metal alloys, according to his potential for harm to the environment and public health, for silver, indium or bismuth. However, these proposals may not meet the necessary physical and chemical properties, compromise the quality of the final product and present high cost. The rate of recycling can be a decisive factor in controlling the relationship with lead solder and lead free.

Effect of Lead Intoxication and D-Penicillamine Treatment on Hematological Indices in Rats / Efectos de Intoxicación con Plomo y Tratamiento de D-Penicilamina en índices Hematológicos en Ratas

Lead is one of the most important environmental pollution which is toxic to many organ systems. D-penicillamine (D-P) is a chelator drug which is used for treatment of lead toxicity for several years. This study was conducted in order to evaluate the efficacy of D-P in reducing the effects of lead on hematological indices. This study was done on 36 male adult, 6-8 weeks albino Wistar rats in Gorgan University of Medical Sciences. At first male adult rats were exposed to lead acetate in their drinking water. After 8 weeks, 6 rats were selected and blood samples were prepared to assess the effects of lead toxicity. The remained lead exposed rats were divided into recovery and treatment groups where distilled water and D-P was administered for them, respectively. After lead exposure, red blood cell count increased slightly, but hemoglobin and hematocrite were decreased. Also MCV and MCH were significantly decreased (P<0.05). RDW, PDW and MPV were significantly higher in lead exposed rats (P<0.05). After recovery period, most of parameters were close to normal while there were no significant differences between recovery and treatment groups. This study showed that hematologic effects of lead are reversible and D-P administration do not play an important role in subchronic lead intoxication.

El plomo es uno de los más importantes contaminantes ambientales, tóxico para la mayoría de los sistemas orgánicos. La D-penicillamina (D-P) es una droga quelante, la cual se ha usado para el tratamiento de la toxicidad por plomo durante varios años. Este estudio fue dirigido para evaluar la eficacia de la D-P en la reducción de los efectos del plomo en los índices hematológicos. Este estudio se realizó en 36 machos adultos de ratas Wistar albinas de 6-8 semanas, en la Universidad de Ciencias Médicas de Gorgan, Irán. Al inicio, las ratas machos adultas fueron expuestas al acetato de plomo en el agua de beber. Después de 8 semanas, 6 ratas se seleccionaron para evaluar los efectos de la toxicidad del plomo en muestras sanguíneas. Las restantes ratas expuestas fueron divididas para su recuperación, a las cuales se les administró agua destilada y un grupo con tratamiento al que se le suministró D-P. Después de la exposición al plomo, el conteo de glóbulos rojos se incrementó ligeramente, pero la hemoglobina y el hematocrito disminuyeron. También el MCV y el valor de MCH disminuyeron significativamente (P< 0,05). Los valores de RDW, PDW y MPV fueron significativamente altos en las ratas expuestas al plomo (p< 0,05). Luego del periodo de recuperación, la mayoría de los parámetros se acercaron al valor normal y no hubo diferencias significativas entre el grupo recuperado y con tratamiento. Este estudio mostró que los efectos hematológicos del plomo son reversibles y la administración de D-P no juega un rol importante en la intoxicación subcrónica.

Effects of YinlingⅠon Cell Viability and Oxidative Injury of Lead-Exposed Vero Cell / 实用儿科临床杂志

Objective To study effects of yinlingⅠon cell viability and oxidative injury of lead-exposed cell.Methods After lead exposure Vero cell was treated with yinlingⅠof different concentrations.The cell viablitity was measured by methyl thiaxiolyl tetrazolium(MTT) method and the superoxide dismutase(SOD)and malondialdehyde(MDA) activity in cell suspensions were measured.Results When Vero cell lived in 125 ?mol/L lead acetate surrounding,the MDA concentration increased,but the viability of cell and the SOD content in the Vero cell suspension decreased.YinlingⅠcould increase the viability of lead-exposed cell during a certain extent;in the most non-toxicity concentration yinlingⅠcould elevate the SOD content in the Vero cell suspension,reduced the MDA concentration and resisting lead toxication in vitro.Conclusion YinlingⅠhas the protective effects on the cell viability and oxidative injury of lead-exposed cell.

Effects of Chitosan on the Lead Level and Histological Changes in Rats Exposed to Various Levels of Lead

Chitosan, which is a biopolymer, composed of glucosamine units linked by beta-1, 4 glycoside bonds, is rich in shells of crustacean such as crabs and shrimps. Consumption of chitosan has been rapidly increased as a functional food. We examined effects of chitosan on the damages caused by lead (Pb) exposure in rats. Male Sprague-Dawley rats were divided into 8 groups (n = 64), then fed diets containing 3% cellulose (control) or 3% chitosan, each with 4 different lead doses (0 mg/d, 20 mg/d, 50 mg/d, and 100 mg/d) for 4 wks. Lead doses were given 3 times per week by oral administration. Blood lead levels in rats increased depending on the administered doses of lead. Rats fed chitosan diets showed lower blood lead concentration than did their respective controls. Effect of chitosan on the blood lead was more beneficial in rats exposed to lower lead (20 mg/d) than in rats exposed to higher lead (50 mg/d and 100 mg/d). Histological changes in erythrocytes and liver were also examined. Chitosan tended to reduce numbers of basophilic stippling erythrocytes and improve the histological liver changes in rats given various lead doses. The preventive effects of chitosan on liver damages were stronger in rats with higher lead than those with lower lead. These results indicate that chitosan has beneficial effects on both blood toxicological responses and histological damages of erythrocytes and liver induced by the administration of various lead doses.

LEAD TOXICITY ON PITUITARY, OVARY AND PLACENTA OF PREGNANT RAT AND HUMAN CHORIONIC VILLI OF PLACENTA / 解剖学报

Female rats were fed with lead acetate 100mg/kg/day(group Ⅰ) or 200 mg/kg/day (group Ⅱ) for 5 days, at the day 7 to 11 of gestation prior to killing. The results shown that the mean level of blood lead in rats of group I was 27.90?8.47?g/dl, and corpus luteum or placenta were injured lightly. In the group Ⅱ, the level of blood lead reached 48.77?16.15?g/dl which correspond to human subacute intoxication, the structure of corpus luteum and placenta were injured prominently, and the activity of 3-hydroxysteroid dehydrogenase is lower than that of control group, about 1/20 of latter. The number of embryos in group Ⅱ were absorbed about 31.69%. However, the gonadotropic cells of pituitary did not affected prominently after treatment with lead. The human chorionic villi of placenta were cultured in medium with lead acetate 0.51?g/ml, 2.5?g/ml, 5?g/ml respectively, for 3 to 4 days. The struture of chorionic villi were damaged obviously after culture with lead more than 2.51?g/ml, and the concentration of hCG in culture medium was decreased. The results indicated that lead affected the corpus luteum, placenta and embryo, and exerted direct action on human trophoblast.