Lead toxicity: An overview of prevalence in Indians

Assessment of prevalence of elevated blood lead levels and risk factors among children and pregnant women in Bihar, India

BACKGROUND

While modeled estimates and studies in contaminated areas indicate high lead exposure among children in Bihar, India, local data on lead exposure in the child population is limited.

OBJECTIVES

To characterize lead exposure, and assess potential sources of lead exposure among a state-representative sample of children and their pregnant mothers residing in Bihar.

METHODS

Blood samples were collected from 697 children under five and 55 pregnant women from eight districts in Bihar. Blood lead levels were determined using capillary blood and a portable lead analyzer. Household demographics, home environment, behavior, and nutrition information were collected through computer-assisted personal interviews with primary caregivers. Logistic regression was used to assess associations between potential risk factors and elevated blood lead levels.

RESULTS

More than 90% of children and 80% of pregnant women reported blood lead levels ≥5 μg/dL. Living near a lead-related industry and pica behavior of eating soil were significantly associated with increased odds of having elevated blood lead levels. Additional risk factors for having a blood level ≥5 μg/dL included the use of skin lightning cream (aOR = 5.11, 95%CI: 1.62, 16.16) and the use of eyeliners (aOR = 2.81, 95%CI: 1.14, 6.93). Having blood lead levels ≥10 μg/dL was also significantly associated with the household member who had an occupation or hobby involving the use of lead (aOR = 1.75, 95%CI: 1.13, 2.72).

DISCUSSION

Elevated blood lead levels were prevalent among children and pregnant women in Bihar, indicating the urgent need for a comprehensive lead poisoning prevention strategy.

Smartphone-Based Rapid Quantitative Detection Platform with Imprinted Polymer for Pb (II) Detection in Real Samples

This paper reports the successful development and application of an efficient method for quantifying Pb2+ in aqueous samples using a smartphone-based colorimetric device with an imprinted polymer (IIP). The IIP was synthesized by modifying the previous study; using rhodizonate, 2-acrylamido-2-methylpropane sulfonic acid (AMPS), N,N'-methylenebisacrylamide (MBA), and potassium persulfate (KPS). The polymers were then characterized. An absorption study was performed to determine the optimal conditions for the smartphone-based colorimetric device processing. The device consists of a black box (10 × 10 × 10 cm), which was designed to ensure repeatability of the image acquisition. The methodology involved the use of a smartphone camera to capture images of IIP previously exposed at Pb2+ solutions with various concentrations, and color channel values were calculated (RGB, YMK HSVI). PLS multivariate regression was performed, and the optimum working range (0-10 mg L-1) was determined using seven principal components with a detection limit (LOD) of 0.215 mg L-1 and R2 = 0.998. The applicability of a colorimetric sensor in real samples showed a coefficient of variation (% RSD) of less than 9%, and inductively coupled plasma mass spectrometry (ICP-MS) was applied as the reference method. These results confirmed that the quantitation smartphone-based colorimetric sensor is a suitable analytical tool for reliable on-site Pb2+ monitoring.

Exogenous application of jasmonates and brassinosteroids alleviates lead toxicity in bamboo by altering biochemical and physiological attributes

Exogenous application of phytohormones is getting promising results in alleviating abiotic stresses, particularly heavy metal (HMs). Jasmonate (JA) and brassinosteroid (BR) have crosstalk in bamboo plants, reflecting a burgeoning area of investigation. Lead (Pb) is the most common pollutant in the environment, adversely affecting plants and human health. The current study focused on the foliar application of 10 µM JA and 10 µM BR in both single and combination forms on bamboo plants grown under Pb stress (0, 50, 100, 150 µM) with a completely randomized design by four replications. The study found that applying 10 µM JA and 10 µM BR significantly improves growth and tolerance by reducing oxidative stress, reactive oxygen species including hydrogen peroxide (H2O2, 32.91%), superoxide radicals (O2-•, 33.9%), methylglyoxal (MG, 19%), membrane lipoperoxidation (25.66%), and electrolyte leakage (41.5%) while increasing antioxidant (SOD (18%), POD (13%), CAT (20%), APX (12%), and GR (19%)), non-antioxidant (total phenolics (7%), flavonols (12.3%), and tocopherols (13.8%)), and glyoxylate activity (GLyI (13%), GLyII (19%)), proline content (19%), plant metal chelating capacity (17.3%), photosynthetic pigments (16%), plant growth (10%), and biomass (12%). We found that JA and BR, in concert, boost bamboo species' Pb tolerance by enhancing antioxidant and glyoxalase cycles, ion chelation, and reducing metal translocation and accumulation. This conclusively demonstrates that utilizing a BR-JA combination form at 10 µM dose may have the potential to yield optimal efficiency in mitigating oxidative stress in bamboo plants.

Benefits of fermented synbiotic soymilk containing Lactobacillus acidophilus, Bifidobacterium lactis, and inulin towards lead toxicity alleviation

This study aims to evaluate the effect of fermented synbiotic soy milk containing Lactobacillus acidophilus, Bifidobacterium lactis, and inulin on a series of hematological and oxidative stress parameters, as well as serum lead levels in rats. In this study, 56 male Sprague-Dawley rats were randomly assigned to assess probiotics (L. acidophilus or B. lactis), probiotics with prebiotics (i.e., inulin), and the corresponding controls. Several hematologic parameters (red blood cell (RBC)), hematocrit (HCT) and hemoglobin (Hgb)), serum lead levels, superoxide dismutase (SOD) activity, and malondialdehyde (MDA) presence was measured to evaluate changes on day 42. Although a significant difference was observed in serum lead levels, there were no significant changes in hematological and oxidative stress parameters between the study groups. In conclusion, this study demonstrates that administering synbiotic fermented soy milk containing the probiotic Lactobacillus acidophilus and the prebiotic inulin may significantly improve serum lead levels in rats.

The effect of lead exposure on IQ test scores in children under 12 years: a systematic review and meta-analysis of case-control studies

An inevitable exposure to the toxic heavy metal such as lead in our environmental can have irreversible effects on children's mental performance.In this study, 3316 children in 8 case-control studies were selected for review. The case group was exposed to a concentration of lead above 10 μg/dL, and the control group was exposed to a concentration of less than 10 μg/dL, but the duration of exposure was different among studies, and the subgroup analysis was performed based on this variable.In the subgroup with duration of exposure less than the average of 4.5 years, the difference of IQ test score between two groups was significant (MD = -3.53) (P-value <0.05). Also, in the subgroup with more than 4.5 years of duration, the difference of IQ test score was significant (MD = -22.63) (P-value < 0.001).This study demonstrates that the concentration and duration of lead exposure have a large effect on mental function in children.

The Elemental Characteristics and Human Health Risk of PM2.5 during Haze Episode and Non-Haze Episode in Chiang Rai Province, Thailand

Fine particle matter (PM_2.5) was directly related to seasonal weather, and has become the influencing factor of air quality that is harmful for human health in Chiang Rai province. The aims were determining the elemental composition in PM_2.5 and human health risk in haze (March 2021) and non-haze episodes (July–August 2021). Nine elements in PM_2.5 were measured by using an Atomic Absorption Spectrophotometer, and an enrichment factor was used to identify the emission source. The results showed that the average concentration of PM_2.5 was 63.07 μg/m³ in haze episodes, and 25.00 μg/m³ in a non-haze episode. The maximum concentration was 116.7 μg/m³ in March. The majority of elements originated from anthropogenic sources. In haze episodes, PM_2.5 mean concentration was approximately 4.2 times that of the WHO guidelines (15 μg/m³ 24 h), and 1.3 times that of the Thai Ambient Air Quality Standard (50 μg/m³). The analysis of backward air mass trajectory showed that transboundary and local sources significantly influenced PM_2.5 at the monitoring site in the sampling period. In the health risk assessment, the non-carcinogenic risk of Cd was the highest, with a Hazard Quotient (HQ) of 0.048, and the cancer risk of Cr was classified as the highest cancer risk, with the values of 1.29 × 10⁻⁵, higher than the minimum acceptable level.

Heavy Metal Contamination of Natural Foods Is a Serious Health Issue: A Review

Heavy metals play an important role in the homeostasis of living cells. However, these elements induce several adverse environmental effects and toxicities, and therefore seriously affect living cells and organisms. In recent years, some heavy metal pollutants have been reported to cause harmful effects on crop quality, and thus affect both food security and human health. For example, chromium, cadmium, copper, lead, and mercury were detected in natural foods. Evidence suggests that these elements are environmental contaminants in natural foods. Consequently, this review highlights the risks of heavy metal contamination of the soil and food crops, and their impact on human health. The data were retrieved from different databases such as Science Direct, PubMed, Google scholar, and the Directory of Open Access Journals. Results show that vegetable and fruit crops grown in polluted soil accumulate higher levels of heavy metals than crops grown in unpolluted soil. Moreover, heavy metals in water, air, and soil can reduce the benefits of eating fruits and vegetables. A healthy diet requires a rational consumption of foods. Physical, chemical, and biological processes have been developed to reduce heavy metal concentration and bioavailability to reduce heavy metal aggregation in the ecosystem. However, mechanisms by which these heavy metals exhibit their action on human health are not well elucidated. In addition, the positive and negative effects of heavy metals are not very well established, suggesting the need for further investigation.

Different Physiological and Biochemical Responses of Bamboo to the Addition of TiO2 NPs under Heavy Metal Toxicity

Bamboo forests cover a remarkable area of Chinese forestland. Recently, titanium dioxide nanoparticles (TiO2 NPs) have been used for plant protection against abiotic stress. In this study, an in vitro tissue culture experiment was conducted to determine the impact of titanium on plant tolerance to two different heavy metals (Cu and Pb). Bamboo plants (Arundinaria pygmaea L.) were grown using five concentrations of TiO2 NPS (0, 50, 80, 100, and 150 µM) without or with 100 µM Cu and 100 µM Pb for 30 days. The results showed that while Cu and Pb increased the generation of Reactive oxygen species (ROS) compounds in plants, TiO2 NP treatments played a positive role in reducing oxidative stress, as indicated by the decrease in ROS compounds, the extent of lipoperoxidation, and soluble proteins. On the other hand, the use of TiO2 NPs increased the total antioxidant capacity, chlorophyll content and general plant biomass. Moreover, the addition of TiO2 NPs significantly reduced Cu, and Pb accumulation in roots, stems, and shoots. We concluded that TiO2 NPs have the ability to reduce oxidative stress in plants by increasing the antioxidant capacity, improving the level of injury, and protecting cell membranes via reducing lipoperoxidation (reduction of Malondialdehyde (MDA) content). However, the results indicated that the efficiency of TiO2 NPs was related to the type and concentration of heavy metal, as TiO2 NPs were more effective for Cu than Pb. Additionally, a high concentration of TiO2 NPs resulted in the greatest enhancement in plant growth and development under heavy metal stress.

Synergistic protective effect of Beta vulgaris with meso-2,3-dimercaptosuccinic acid against lead-induced neurotoxicity in male rats

Lead (Pb) toxicity is one of the most prevalent causes of human neurotoxicity. The available chelator drugs used now have many adverse effects. So, in this study, the protective role of Beta vulgaris juice (BVJ) on rat neurotoxicity induced by Pb was evaluated and the results were compared with the results of dimercaptosuccinic acid (DMSA, as used drug). Additionally, the synergistic effect of BVJ and DMSA against Pb-induced neurotoxicity was assessed. The study focused on the determination of the antioxidant, anti-inflammatory, and neurological potential of BVJ (alone, and with DMSA) towards lead-induced neurotoxicity. Also, the characterization of BVJ was studied. The results showed that BVJ contains considerable quantities of polyphenols, triterpenoids, and betalains which play an important role as antioxidants and anti-inflammatory. BVJ exhibited a protective effect against neurotoxicity via the reduction of Pb levels in blood and brain. Moreover, BVJ decreased the oxidative stress, inflammation, and cell death induced by Pb. Also, BVJ regulated the activities of acetylcholine esterase and monoamine oxidase-A which changed by Pb toxicity. BVJ and DMSA combination displayed a synergistic antineurotoxic effect (combination index ˂ 1). These results were in harmony with brain histopathology. Conclusion: BVJ has a powerful efficacy in the protection from brain toxicity via diminishing Pb in the brain and blood circulation, resulting in the prevention of the oxidative and inflammatory stress. Treatment with BVJ in combination with DMSA revealed a synergistic effect in the reduction of neurotoxicity induced by Pb. Also, the antioxidant and anti-inflammatory effects of the BVJ lead to the improvement of DMSA therapy.

Nigella sativaand its Derivatives as Food Toxicity Protectant Agents

Exposure to food toxins generate multiple adverse health effects. Heavy metals, antibiotics residue, mycotoxins, pesticides and some food additives are examples of the most important food toxins. The common mechanism of toxicity and carcinogenicity effects of food toxins is the generation of oxidative stress that leads to DNA damages. Moreover, based on epidemiologic evidence unhealthy eating habits and food toxicities are associated with cancers occurrence. Therefore, application of bioactive food additives as harmless or safe components in food industry is expensive. Nigella sativa L. is a broadly used herb-drug for various diseases all over the world and has been used as preservative and food additive. Based on various studies N. sativa has shown various pharmacological activities including therapeutic efficacy against different human diseases and antioxidant anti-inflammatory effects against environmental toxins. N. sativa decreases the adverse health effects induced by mentioned food toxins via modulating the action of antioxidant enzymes such as glutathione peroxidase (GPx), glutathione-S-transferase catalase and act as reactive oxygen species (ROS) scavengers in different organs. Besides, N. sativa and thymoquinone (TQ) have protective effects on food products through removal and inhibition of various toxic compounds. Therefore, in the present review we will describe all protective effects of N. sativa and its main constituents, TQ, against food induced toxicities.

A meta-analysis of blood lead levels in India and the attributable burden of disease

Multiple studies in India have found elevated blood lead levels (BLLs) in target populations. However the data have not yet been evaluated to understand population-wide exposure levels. We used arithmetic mean blood lead data published from 2010 to 2018 on Indian populations to calculate the average BLLs for multiple subgroups. We then calculated the attributable disease burden in IQ decrement and Disability Adjusted Life Years (DALYs). Our Pubmed search yielded 1066 articles. Of these, 31 studies representing the BLLs of 5472 people in 9 states met our study criteria. Evaluating these, we found a mean BLL of 6.86 μg/dL (95% CI: 4.38-9.35) in children and 7.52 μg/dL (95% CI: 5.28-9.76) in non-occupationally exposed adults. We calculated that these exposures resulted in 4.9 million DALYs (95% CI: 3.9-5.6) in the states we evaluated. Population-wide BLLs in India remain elevated despite regulatory action to eliminate leaded petrol, the most significant historical source. The estimated attributable disease burden is larger than previously calculated, particularly with regard to associated intellectual disability outcomes in children. Larger population-wide BLL studies are required to inform future calculations. Policy responses need to be developed to mitigate the worst exposures.

Leachable lead and cadmium in microwave-heated ceramic cups: possible health hazard to human

In this study, we assessed the leachability as well as health risk associated with the consumption from glazed, colourful, ceramic cups, containing lead and cadmium. Both metals leached into the 2.5-min microwave-heated (convection mode, at 140 °C) double-distilled water in concentrations above 0.5 mg/L, the permissible limits of leachable Pb and Cd in ceramic mugs set by United States Food and Drug Administration (US FDA). On an average, significantly higher Pb leached in new cups, 7.69 ± 0.56 mg/L, compared to that in old cups, 3.15 ± 0.15 mg/L. Cd leached similarly in both old (1.97 ± 0.14 mg/L) and new cups (1.57 ± 0.005 mg/L). The chronic daily intake of Pb by children and adults, respectively, consuming from new cups were 1.3-5× and 1.28-6× more than that from old cups. In both the cases, intake values far exceeded WHO reference dose of 0.0006 mg Pb/kg bw/day in children (< 11 years) and 0.0013 mg Pb/kg bw/day in adults. Such levels of Pb consumption in children might be predicted to be associated with decrement in IQ by at least 1 point and adverse effects in adults, especially, women of childbearing age. The daily intake of Cd from these cups ranged from 0.002-0.049 mg/kg bw/day, which was also above permissible limit. Consequently, high hazard quotient and hazard index (both more than 1) were observed for these metals, which might impart individual as well as cumulative effects on the health. Thus, apart from other dietary as well as inhalation sources of contaminants (which were not studied here), regular consumption of beverages alone in glazed, ceramic cups increased chances of Pb- and Cd-related health risks to humans.