Rapid Market Screening to assess lead concentrations in consumer products across 25 low- and middle-income countries.

Lead exposure can have serious consequences for health and development. The neurological and behavioral effects of lead are considered irreversible. Young children are particularly vulnerable to lead poisoning. In 2020, Pure Earth and UNICEF estimated that one in three children had elevated blood lead levels above 5 µg/dL. The sources of lead exposure vary around the world and can range from household products, such as spices or foodware, to environmental pollution from nearby industries. The aim of this study was to analyze common products from markets in low- and middle-income countries (LMICs) for their lead content to determine whether they are plausible sources of exposure. In 25 LMICs, the research teams systematically collected consumer products (metal foodware, ceramics, cosmetics, paints, toys, spices and other foods). The items were analyzed on site for detectable lead above 2 ppm using an X-ray fluorescence analyzer. For quality control purposes, a subset of the samples was analyzed in the USA using inductively coupled plasma mass spectrometry. The lead concentrations of the individual product types were compared with established regulatory thresholds. Out of 5007 analyzed products, threshold values (TV) were surpassed in 51% for metal foodware (TV 100 ppm), 45% for ceramics (TV 100 ppm), and 41% for paints (TV 90 ppm). Sources of exposure in LMICs can be diverse, and consumers in LMICs lack adequate protection from preventable sources of lead exposure. Rapid Market Screening is an innovative, simple, and useful tool to identify risky products that could be sources of lead exposure.

Reductions in spice lead levels in the republic of Georgia: 2020-2022.

Spice adulteration using yellow lead chromate-based pigments has been documented as a growing global health concern. Spices from the Republic of Georgia with extremely high levels of lead, up to an order of magnitude higher than any other spices worldwide, have been implicated as sources of child lead poisoning. The objectives of this study were to 1) evaluate lead concentrations in spices sampled across the country of Georgia between 2020 and 2022, and 2) assess factors associated with spice adulteration, specifically the role of spice quality and regulatory enforcement. Spice samples were collected from 29 cities nationwide. The most populous cities were selected in each administrative region as well as those of importance to the spice supply chain. Sampling was carried out at the largest spice bazaars in each city. The regions of Adjara and Imereti were the focus of qualitative interviews conducted in 2021 with key businesspeople selling spices with very high and low levels of lead. The same cities and bazaars were visited at each of three sampling periods between 2020 and 2022. In total, 765 spice samples were collected. Lead concentrations in spices decreased over time, with a maximum of 14,233 µg/g in 2020 down to 36 µg/g in the final sampling round of 2022. A logistic regression determined that sampling round, region and spice type were associated with elevated lead in samples. Samples from Adjara and those containing marigold had the highest lead levels. Interviews with eighteen prominent spice vendors revealed difficulties sourcing sufficient quantities of high quality, brightly colored marigold, and concerns about adulteration. Interviews with two authorities from the National Food Authority highlighted the increased attention on regulating lead in spices since 2018. Continued monitoring and periodic regulatory enforcement may adequately disincentivize further adulteration with lead chromate in the spice industry in Georgia.

Food safety policy enforcement and associated actions reduce lead chromate adulteration in turmeric across Bangladesh.

Turmeric adulterated with lead chromate pigment has been previously identified as a primary source of lead exposure in Bangladesh. This study assesses the impact of a multi-faceted intervention between 2017 and 2021 to reduce lead-tainted turmeric in Bangladesh. The intervention involved: i) disseminating findings from scientific studies via news media that identified turmeric as a source of lead poisoning, ii) educating consumers and businesspeople about the risks of lead chromate in turmeric via public notices and face-to-face meetings, and iii) collaborating with the Bangladesh Food Safety Authority to utilize a rapid lead detection technology to enforce policy disallowing turmeric adulteration. Before and after the intervention, evidence of lead chromate turmeric adulteration was assessed at the nation's largest turmeric wholesale market and at turmeric polishing mills across the country. Blood lead levels of workers at two mills were also assessed. Forty-seven interviews were conducted with consumers, businesspeople, and government officials to assess changes in supply, demand, and regulatory capacity. The proportion of market turmeric samples containing detectable lead decreased from 47% pre-intervention in 2019 to 0% in 2021 (n = 631, p < 0.0001). The proportion of mills with direct evidence of lead chromate adulteration (pigment on-site) decreased from 30% pre-intervention in 2017 to 0% in 2021 (n = 33, p < 0.0001). Blood lead levels dropped a median of 30% (IQR: 21-43%), while the 90th percentile dropped 49% from 18.2 µg/dL to 9.2 µg/dL 16 months after the intervention (n = 15, p = 0.033). Media attention, credible information, rapid lead detection tools and swift government action to enforce penalties all contributed to the intervention's success. Subsequent efforts should evaluate if this is an example of an effective intervention that can be replicated to reduce lead chromate adulteration of spices globally.

Assessing Analytical Methods for the Rapid Detection of Lead Adulteration in the Global Spice Market.

Lead adulteration of spices, primarily via Pb chromate compounds, has been documented globally as a growing public health concern. Currently, Pb detection in spices relies primarily on expensive and time-consuming laboratory analyses. Advancing rapid Pb detection methods, inclusive of their accuracy and precision, would improve field assessments by food safety inspectors, stakeholders, and the public in the hope of reducing Pb exposure risks at its source. Here, we present two field procedures for Pb detection: portable X-ray fluorescence analysis (pXRF) and a simple colorimetric test. We assess their efficacy to detect Pb and its chemical form in seven spice types, including powders, spice-salt mixtures, and dried roots, compared to the proven laboratory technique, inductively coupled plasma mass spectrometry (ICP-MS). Lead concentrations measured using pXRF and ICP-MS were within 5% of each other for spice powders and 24% for dried roots. By pXRF, spice samples were analyzed within collection plastic bags without preparation, resulting in a detection limit of 2 mg Pb/kg for spice powders, which is comparable to national food standards. The colorimetric test utilized here targets hexavalent chromium, making the method selective to Pb chromate adulteration assuming that this is its dominant source in spices. Color development, and thus detection, was observed when Pb concentrations exceeded approximately 5-70 mg/kg in dried turmeric roots and 1000 mg/kg in spice powders; however, it was ineffective for the spice-salt mixture. We show that pXRF analysis and a colorimetric assay provide information that may improve field decisions about Pb adulteration in a range of spice types, helping to minimize Pb exposure.

Lead exposure and antisocial behavior: A systematic review protocol.

BACKGROUND: Lead exposure remains highly prevalent worldwide despite decades of research highlighting its link to numerous adverse health outcomes. In addition to well-documented effects on cognition, there is growing evidence of an association with antisocial behavior, including aggression, conduct problems, and crime. An updated systematic review on this topic, incorporating study evaluation and a developmental perspective on the outcome, can advance the state of the science on lead and inform global policy interventions to reduce exposure. OBJECTIVES: We aim to evaluate the link between lead exposure and antisocial behavior. This association will be investigated via a systematic review of human epidemiological and experimental nonhuman mammalian studies. METHODS: The systematic review protocol presented in this publication is informed by recommendations for the conduct of systematic reviews in toxicology and environmental health research (COSTER) and follows the study evaluation approach put forth by the U.S. EPA Integrated Risk Information System (IRIS) program. DATA SOURCES: We will search the following electronic databases for relevant literature: PubMed, BIOSIS and Web of Science. Search results will be stored in EPA's Health and Environmental Research Online (HERO) database. STUDY ELIGIBILITY AND CRITERIA: Eligible human epidemiological studies will include those evaluating any population exposed to lead at any lifestage via ingestion or inhalation exposure and considering an outcome of antisocial behavior based on any of the following criteria: psychiatric diagnoses (e.g., oppositional defiant disorder (ODD), conduct disorder (CD), disruptive behavior disorders (DBD)); violation of social norms (e.g., delinquency, criminality); and aggression. Eligible experimental animal studies will include those evaluating nonhuman mammalian studies exposed to lead via ingestion, inhalation, or injection exposure during any lifestage. The following outcomes will be considered relevant: aggression; antisocial behavior; and altered fear, anxiety, and stress response. STUDY APPRAISAL AND SYNTHESIS METHODS: Screening will be conducted with assistance from an artificial intelligence application. Two independent reviewers for each data stream (human, animal) will screen studies with highest predicted relevance against pre-specified inclusion criteria at the title/abstract and full-text level. Study evaluation will be conducted using methods adapted from the U.S. EPA IRIS program. After data extraction, we will conduct a narrative review and quantitative meta-analysis on the human epidemiological studies as well as a narrative review of the experimental animal studies. We will evaluate the strength of each evidence stream separately and then will develop a summary evidence integration statement based on inference across evidence streams.

Larval source reduction with a purpose: Designing and evaluating a household- and school-based intervention in coastal Kenya.

BACKGROUND: Since Aedes aegypti mosquitoes preferentially breed in domestic containers, control efforts focus on larval source reduction. Our objectives were to design and test the effectiveness of a source reduction intervention to improve caregiver knowledge and behaviors in coastal Kenya. METHODOLOGY/PRINCIPAL FINDINGS: We conducted a cluster-randomized controlled trial with 261 households from 5 control villages and 259 households from 5 intervention villages. From each household, one child (10-16 years old) and his or her primary caregiver participated in the intervention. We assessed caregiver knowledge and behavior at baseline, as well as 3 and 12 months after the intervention. We assessed household entomological indices at baseline and 12 months after the intervention to avoid seasonal interference. We conducted qualitative interviews with 34 caregivers to understand barriers and facilitators to change. We counted and weighed containers collected by children and parents during a community container clean-up and recycling event. After 12 months, caregiver knowledge about and self-reported behavior related to at least one source reduction technique was more than 50 percentage points higher in the intervention compared to control arm (adjusted risk differences for knowledge: 0.69, 95% CI [0.56 to 0.82], and behavior: 0.58 [0.43 to 0.73]). Respondents stated that other family members' actions were the primary barriers to proper container management. The number of containers at households did not differ significantly across arms even though children and parents collected 17,200 containers (1 ton of plastics) which were used to planted 4,000 native trees as part of the community event. CONCLUSIONS/SIGNIFICANCE: Our study demonstrates that source reduction interventions can be effective if designed with an understanding of the social and entomological context. Further, source reduction is not an individual issue, but rather a social/communal issue, requiring the participation of other household and community members to be sustained.

Effects of the COVID-19 pandemic on caregiver mental health and the child caregiving environment in a low-resource, rural context.

Early child development has been influenced directly and indirectly by the COVID-19 pandemic, and these effects are exacerbated in contexts of poverty. This study estimates effects of the pandemic and subsequent population lockdowns on mental health, caregiving practices, and freedom of movement among female caregivers of children 6-27 months (50% female), in rural Bangladesh. A cohort (N = 517) was assessed before and during the pandemic (May-June, 2019 and July-September, 2020). Caregivers who experienced more food insecurity and financial loss during the pandemic reported larger increases in depressive symptoms (0.26 SD, 95% CI 0.08-0.44; 0.21 SD, 0.04-0.40) compared to less affected caregivers. Stimulating caregiving and freedom of movement results were inconsistent. Increases in depressive symptoms during the pandemic may have consequences for child development.

Making the invisible visible: Developing and evaluating an intervention to raise awareness and reduce lead exposure among children and their caregivers in rural Bangladesh.

Lead exposure is harmful at any time in life, but pre-natal and early childhood exposures are particularly detrimental to cognitive development. In Bangladesh, multiple household-level lead exposures pose risks, including turmeric adulterated with lead chromate and food storage in lead-soldered cans. We developed and evaluated an intervention to reduce lead exposure among children and their caregivers in rural Bangladesh. We conducted formative research to inform theory-based behavioral recommendations. Lead exposure was one of several topics covered in the multi-component intervention focused on early child development. Community health workers (CHWs) delivered the lead component of the intervention during group sessions with pregnant women and mother-child dyads (<15 months old) in a cluster-randomized trial. We administered household surveys at baseline (control n = 301; intervention n = 320) and 9 months later at endline (control n = 279; intervention n = 239) and calculated adjusted risk and mean differences for primary outcomes. We conducted two qualitative assessments, one after 3 months and a second after 9 months, to examine the feasibility and benefits of the intervention. At endline, the prevalence of lead awareness was 52 percentage points higher in the intervention arm compared to the control (adjusted risk difference: 0.52 [95% CI 0.46 to 0.61]). Safe turmeric consumption and food storage practices were more common in the intervention versus control arm at endline, with adjusted risk differences of 0.22 [0.10 to 0.32] and 0.13 [0.00 to 0.19], respectively. Semi-structured interviews conducted with a subset of participants after the intervention revealed that the perceived benefit of reducing lead exposure was high because of the long-term negative impacts that lead can have on child cognitive development. The study demonstrates that a group-based CHW-led intervention can effectively raise awareness about and motivate lead exposure prevention behaviors in rural Bangladesh. Future efforts should combine similar awareness-raising efforts with longer-term regulatory and structural changes to systematically and sustainably reduce lead exposure.

A holistic approach to promoting early child development: a cluster randomised trial of a group-based, multicomponent intervention in rural Bangladesh.

INTRODUCTION: In low- and middle-income countries, children experience multiple risks for delayed development. We evaluated a multicomponent, group-based early child development intervention including behavioural recommendations on responsive stimulation, nutrition, water, sanitation, hygiene, mental health and lead exposure prevention. METHODS: We conducted a 9-month, parallel, multiarm, cluster-randomised controlled trial in 31 rural villages in Kishoreganj District, Bangladesh. Villages were randomly allocated to: group sessions ('group'); alternating groups and home visits ('combined'); or a passive control arm. Sessions were delivered fortnightly by trained community members. The primary outcome was child stimulation (Family Care Indicators); the secondary outcome was child development (Ages and Stages Questionnaire Inventory, ASQi). Other outcomes included dietary diversity, latrine status, use of a child potty, handwashing infrastructure, caregiver mental health and knowledge of lead. Analyses were intention to treat. Data collectors were independent from implementers. RESULTS: In July-August 2017, 621 pregnant women and primary caregivers of children<15 months were enrolled (group n=160, combined n=160, control n=301). At endline, immediately following intervention completion (July-August 2018), 574 participants were assessed (group n=144, combined n=149, control n=281). Primary caregivers in both intervention arms participated in more play activities than control caregivers (age-adjusted means: group 4.22, 95% CI 3.97 to 4.47; combined 4.77, 4.60 to 4.96; control 3.24, 3.05 to 3.39), and provided a larger variety of play materials (age-adjusted means: group 3.63, 3.31 to 3.96; combined 3.81, 3.62 to 3.99; control 2.48, 2.34 to 2.59). Compared with the control arm, children in the group arm had higher total ASQi scores (adjusted mean difference in standardised scores: 0.39, 0.15 to 0.64), while in the combined arm scores were not significantly different from the control (0.25, -0.07 to 0.54). CONCLUSION: Our findings suggest that group-based, multicomponent interventions can be effective at improving child development outcomes in rural Bangladesh, and that they have the potential to be delivered at scale. TRIAL REGISTRATION NUMBER: The trial is registered in ISRCTN (ISRCTN16001234).

Child lead exposure near abandoned lead acid battery recycling sites in a residential community in Bangladesh: Risk factors and the impact of soil remediation on blood lead levels.

Lead is a potent neurotoxin that is particularly detrimental to children's cognitive development. Batteries account for at least 80% of global lead use and unsafe battery recycling is a major contributor to childhood lead poisoning. Our objectives were to assess the intensity and nature of child lead exposure at abandoned, informal used lead acid battery (ULAB) recycling sites in Kathgora, Savar, Bangladesh, as well as to assess the feasibility and effectiveness of a soil remediation effort to reduce exposure. ULAB recycling operations were abandoned in 2016 due to complaints from residents, but the lead contamination remained in the soil after operations ceased. We measured soil and blood lead levels (BLLs) among 69 children living within 200 m of the ULAB recycling site once before, and twice after (7 and 14 months after), a multi-part remediation intervention involving soil capping, household cleaning, and awareness-raising activities. Due to attrition, the sample size of children decreased from 69 to 47 children at the 7-month post-intervention assessment and further to 25 children at 14 months. We conducted non-parametric tests to assess changes in soil lead levels and BLLs. We conducted baseline surveys, as well as semi-structured interviews and observations with residents throughout the study period to characterize exposure behaviors and the community perceptions. We conducted bivariate and multivariate regression analyses of exposure characteristics to determine the strongest predictors of baseline child BLLs. Prior to remediation, median soil lead concentrations were 1400 mg/kg, with a maximum of 119,000 mg/kg and dropped to a median of 55 mg/kg after remediation (p < 0.0001). Among the 47 children with both baseline and post-intervention time 1 measurements, BLLs dropped from a median of 21.3 µg/dL to 17.0 µg/dL at 7 months (p < 0.0001). Among the 25 children with all three measurements, BLLs dropped from a median of 22.6 µg/dL to 14.8 µg/dL after 14 months (p < 0.0001). At baseline, distance from a child's residence to the nearest abandoned ULAB site was the strongest predictor of BLLs and baseline BLLs were 31% higher for children living within 50 m from the sites compared to those living further away (n = 69, p = 0.028). Women and children spent time in the contaminated site daily and relied on it for their livelihoods and for recreation. Overall, this study highlights the intensity of lead exposure associated with the ULAB recycling industry. Additionally, we document the feasibility and effectiveness of a multi-part remediation intervention at a contaminated site embedded within a residential community; substantially reducing child BLLs and soil lead concentrations.

Source reduction with a purpose: Mosquito ecology and community perspectives offer insights for improving household mosquito management in coastal Kenya.

Understanding mosquito breeding behavior as well as human perspectives and practices are crucial for designing interventions to control Aedes aegypti mosquito-borne diseases as these mosquitoes primarily breed in water-holding containers around people's homes. The objectives of this study were to identify productive mosquito breeding habitats in coastal Kenya and to understand household mosquito management behaviors and their behavioral determinants. The field team conducted entomological surveys in 444 households and semi-structured interviews with 35 female caregivers and 37 children in Kwale County, coastal Kenya, between May and December 2016. All potential mosquito habitats with or without water were located, abundances of mosquito immatures measured and their characteristics recorded. Interviews explored household mosquito management behaviors and their behavioral determinants. 2,452 container mosquito habitats were counted containing 1,077 larvae and 390 pupae, predominantly Aedes species. More than one-third of the positive containers were found outside houses in 1 of the 10 villages. Containers holding water with no intended purpose contained 55.2% of all immature mosquitoes. Containers filled with rainwater held 95.8% of all immature mosquitoes. Interviews indicated that households prioritize sleeping under bednets as a primary protection against mosquito-borne disease because of concern about night-time biting, malaria-transmitting Anopheles mosquitoes. Respondents had limited knowledge about the mosquito life cycle, especially with respect to day-time biting, container-breeding Aedes mosquitoes. Therefore, respondents did not prioritize source reduction. Most mosquitoes breed in containers that have no direct or immediate purpose ("no-purpose containers"). These containers may be left unattended for several days allowing rainwater to collect, and creating ideal conditions for mosquito breeding. An intervention that requires little effort and targets only the most productive containers could effectively reduce mosquito indices and, relatedly, mosquito-borne disease risk.

Turmeric means "yellow" in Bengali: Lead chromate pigments added to turmeric threaten public health across Bangladesh.

Adulteration is a growing food safety concern worldwide. Previous studies have implicated turmeric as a source of lead (Pb) exposure due to the addition of lead chromate (PbCrO4), a yellow pigment used to enhance brightness. We aimed to assess the practice of adding yellow pigments to turmeric and producer- consumer- and regulatory-factors affecting this practice across the supply chain in Bangladesh. We identified and visited the nine major turmeric-producing districts of Bangladesh as well as two districts with minimal turmeric production. In each district, we conducted semi-structured interviews and informal observations with individuals involved in the production, consumption, and regulation of turmeric. We explored perceptions of and preferences for turmeric quality. We collected samples of yellow pigments and turmeric from the most-frequented wholesale and retail markets. We collected samples of turmeric, pigments, dust, and soil from turmeric polishing mills to assess evidence of adulteration. Interviews were analyzed through an inductive, thematic coding process, with attention focused on perceptions of and preferences for turmeric quality. Samples were analyzed for Pb and chromium (Cr) concentrations via inductively coupled plasma mass spectrometry and x-ray fluorescence. In total, we interviewed 152 individuals from across the supply chain and collected 524 samples of turmeric, pigments, dust, and soil (Table S3, Table S4). Turmeric Pb and Cr concentrations were highest in Dhaka and Munshiganj districts, with maximum turmeric powder Pb concentrations of 1152 µg/g, compared to 690 µg/g in the 9 major turmeric-producing districts. We found evidence of PbCrO4-based yellow pigment adulteration in 7 of the 9 major turmeric-producing districts. Soil samples from polishing mills contained a maximum of 4257 µg/g Pb and yellow pigments contained 2-10% Pb by weight with an average Pb:Cr molar ratio of 1.3. Turmeric wholesalers reported that the practice of adding yellow pigments to dried turmeric root during polishing began more than 30 years ago and continues today, primarily driven by consumer preferences for colorful yellow curries. Farmers stated that merchants are able to sell otherwise poor-quality roots and increase their profits by asking polishers to adulterate with yellow pigments. Adulterating turmeric with lead chromate poses significant risks to human health and development. The results from this study indicate that PbCrO4 is being added to turmeric by polishers, who are unaware of its neurotoxic effects, in order to satisfy wholesalers who are driven by consumer demand for yellow roots. We recommend immediate intervention that engages turmeric producers and consumers to address this public health crisis and ensure a future with Pb-free turmeric.

Sources of Blood Lead Exposure in Rural Bangladesh.

Lead (Pb) exposure is a major public health problem worldwide. Although high levels of Pb in blood in Bangladesh have been documented, the dominant Pb sources contributing to human exposure in rural Bangladesh have not been determined. Here, we first obtained blood from pregnant women from three rural Bangladeshi districts who were previously assessed by a case-control and sampling study, and we then conducted semistructured in-depth interviews to understand Pb exposure behavior and finally collected samples of the suspected Pb sources. We measured the Pb isotopic composition of both potential Pb sources and 45 blood samples in order to understand which of three sources predominate: (1) food from Pb-soldered cans, (2) turmeric, or (3) geophagous materials (clay, soil, or ash). The Pb isotope ratios of the three sources are distinct (p = 0.0001) and blood isotope ratios are most similar to turmeric. Elevated lead and chromium (Cr) concentrations in turmeric and a yellow pigment used in turmeric processing are consistent with reported consumption behavior that indicated turmeric as a primary contributor to blood Pb. The Pb isotopic composition analyses combined with a case-control and sampling approach provides evidence that turmeric adulterated with the yellow Pb-bearing pigment is the main Pb exposure source in these districts and illustrates the need to assess drivers and practices of turmeric adulteration, as well as the prevalence of adulteration across South Asia.

Solid Wastes Provide Breeding Sites, Burrows, and Food for Biological Disease Vectors, and Urban Zoonotic Reservoirs: A Call to Action for Solutions-Based Research.

Background: Infectious disease epidemiology and planetary health literature often cite solid waste and plastic pollution as risk factors for vector-borne diseases and urban zoonoses; however, no rigorous reviews of the risks to human health have been published since 1994. This paper aims to identify research gaps and outline potential solutions to interrupt the vicious cycle of solid wastes; disease vectors and reservoirs; infection and disease; and poverty. Methods: We searched peer-reviewed publications from PubMed, Google Scholar, and Stanford Searchworks, and references from relevant articles using the search terms ("disease" OR "epidemiology") AND ("plastic pollution," "garbage," and "trash," "rubbish," "refuse," OR "solid waste"). Abstracts and reports from meetings were included only when they related directly to previously published work. Only articles published in English, Spanish, or Portuguese through 2018 were included, with a focus on post-1994, after the last comprehensive review was published. Cancer, diabetes, and food chain-specific articles were outside the scope and excluded. After completing the literature review, we further limited the literature to "urban zoonotic and biological vector-borne diseases" or to "zoonotic and biological vector-borne diseases of the urban environment." Results: Urban biological vector-borne diseases, especially Aedes-borne diseases, are associated with solid waste accumulation but vector preferences vary over season and region. Urban zoonosis, especially rodent and canine disease reservoirs, are associated with solid waste in urban settings, especially when garbage accumulates over time, creating burrowing sites and food for reservoirs. Although evidence suggests the link between plastic pollution/solid waste and human disease, measurements are not standardized, confounders are not rigorously controlled, and the quality of evidence varies. Here we propose a framework for solutions-based research in three areas: innovation, education, and policy. Conclusions: Disease epidemics are increasing in scope and scale with urban populations growing, climate change providing newly suitable vector climates, and immunologically naïve populations becoming newly exposed. Sustainable solid waste management is crucial to prevention, specifically in urban environments that favor urban vectors such as Aedes species. We propose that next steps should include more robust epidemiological measurements and propose a framework for solutions-based research.

Prevalence of elevated blood lead levels among pregnant women and sources of lead exposure in rural Bangladesh: A case control study.

Prenatal and early childhood lead exposures impair cognitive development. We aimed to evaluate the prevalence of elevated blood lead levels (BLLs) among pregnant women in rural Bangladesh and to identify sources of lead exposure. We analyzed the BLLs of 430 pregnant women randomly selected from rural communities in central Bangladesh. Fifty-seven cases were selected with the highest BLLs, ≥ 7 µg/dL, and 59 controls were selected with the lowest BLLs, < 2 µg/dL. An exposure questionnaire was administered and soil, rice, turmeric, water, traditional medicine, agrochemical, and can samples were analyzed for lead contamination. Of all 430 women, 132 (31%) had BLLs > 5 µg/dL. Most women with elevated BLLs were spatially clustered. Cases were 2.6 times more likely than controls to consume food from a can (95% CI 1.0-6.3, p = 0.04); 3.6 times more likely to use Basudin, a specific brand of pesticide (95% CI 1.6-7.9, p = 0.002); 3.6 times more likely to use Rifit, a specific brand of herbicide (95% CI 1.7-7.9, p = 0.001); 2.9 times more likely to report using any herbicides (95% CI 1.2-7.3, p = 0.02); and 3.3 times more likely to grind rice (95% CI 1.3-8.4, p = 0.01). Five out of 28 food storage cans were lead-soldered. However, there was minimal physical evidence of lead contamination from 382 agrochemical samples and 129 ground and unground rice samples. Among 17 turmeric samples, one contained excessive lead (265 µg/g) and chromium (49 µg/g). Overall, we found evidence of elevated BLLs and multiple possible sources of lead exposure in rural Bangladesh. Further research should explicate and develop interventions to interrupt these pathways.

Enhanced inactivation of Bacillus subtilis spores during solar photolysis of free available chlorine.

Aqueous free available chlorine (FAC) can be photolyzed by sunlight and/or artificial UV light to generate various reactive oxygen species, including HO(•) and O((3)P). The influence of this chemistry on inactivation of chlorine-resistant microorganisms was investigated using Bacillus subtilis endospores as model microbial agents and simulated and natural solar radiation as light sources. Irradiation of FAC solutions markedly enhanced inactivation of B. subtilis spores in 10 mM phosphate buffer; increasing inactivation rate constants by as much as 600%, shortening inactivation curve lag phase by up to 73% and lowering CTs required for 2 log10 inactivation by as much as 71% at pH 8.0 and 10 °C. Similar results were observed at pH 7.4 and 10 °C in two drinking water samples with respective DOC concentrations and alkalinities of 0.6 and 1.2 mg C/L and 81.8 and 17.1 mg/L as CaCO3. Solar radiation alone did not inactivate B. subtilis spores under the conditions investigated. A variety of experimental data indicate that the observed enhancements in spore inactivation can be attributed to the concomitant attack of spores by HO(•) and O3, the latter of which was found to accumulate to micromolar concentrations during simulated solar irradiation of 10 mM phosphate buffer (pH 8, 10 °C) containing [FAC]0 = 8 mg/L as Cl2.