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Lead is one of the most harmful toxic metals to humans. In Mexico, though most potters still use a lead-based glazing process, a new lead-free glaze has been introduced to the production of pottery. The Approved Pottery Program (APP) promotes the production of lead-free pottery. As a component of the APP, we aimed to document in this pilot study the blood lead levels (BLLs) of a sample of potters and the association with the type of glaze used. A cross-sectional study was conducted based on information from 46 potters grouped by 26 workshops. We measured general sociodemographic characteristics, capillary BLLs, and the lead levels of the dirt floors of the workshops. The evaluation of associations and comparisons between glaze types was performed based on a regression model clustered by workshop. The median BLL measured was 13.6 µg/dl (IQR: 7.8-20.4 µg/dl), and 70% of the BLLs were greater than 10 µg/dl. Workshop managers presented higher BLLs compared to others working in the same workshop (median of 14.1 µg/dl (IQR: 11.6-25.3 µg/dl) versus 10.1 µg/dl (IQR: 5.2-16.7 µg/dl), respectively). The median BLLs of potters who used lead-free glaze in at least 80% of production were 8.8 µg/dl (95% CI: -17.3 to -0.3 µg/dl) lower than the BLLs of those who used lead-free glaze in less than 30% of production, adjusted by workshop role. Additionally, the lead levels were significantly lower in workshop dirt floors where lead-free glaze was used in at least 80% of the production compared to those that use less than 30% (180 versus 916 mg/kg; p < 0.05). The use of lead-free glaze in the production of pottery was associated with both lower BLLs in potters and lower soil lead levels in the workshop area.

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OBJECTIVE: To estimate de magnitude of Pb poisoning (≥5µg/dL blood) in 1-4 year old children and to identify the contribution of lead-glazed ceramics use (LGC) as a source of exposure in the 32 Mexican states. MATERIALS AND METHODS: Using the results from a sample of capillary blood lead (BPb) we estimated the prevalence of Pb poisoning, it's association with LGC and national distribution. RESULTS: The national prevalence of Pb poisoning was 17.4% representing 1.4 million children. The prevalence was 30.7% among LGC users and 11.8% in non-users. In 17 states the prevalence of Pb poisoning was ≥10%, in 11 states between 5-10%, and in 4 states <5%. CONCLUSIONS: There is a geographic differential distribution of the problem; confirming the association with LGC and estimating the contribution of other Pb exposure sources. This information offers a guide to implement preven-tion and control actions in Mexico.

OBJETIVO: Estimar la magnitud de intoxicación por plomo (Pb) (≥5µg/dL en sangre) en niños de 1 a 4 años e identificar la contribución del uso de loza de barro vidriado con Pb (LBVPb) como fuente de exposición en los 32 estados de México. MATERIAL Y MÉTODOS: Muestra de Pb en sangre (PbS) capilar de niños participantes en la Encuesta Nacional de Salud y Nutrición 2018-2019. Se estimó la prevalencia de intoxicación, su asociación con LBVPb y distribución nacional. RESULTADOS: La prevalencia nacional de intoxicación fue 17.4%, lo cual representa 1.4 millones de niños. Esta preva-lencia fue 30.7% entre usuarios de LBVPb y 11.8% entre no usuarios. En 17 estados la prevalencia de intoxicación es ≥10%; en 11 es ≥5-10% y en 4 es <5%. CONCLUSIONES: Existe una distribución diferencial geográfica del problema; se confirma la asociación con LBVPb y se estima la contribución de otras fuentes de exposición. Esta información ofrece una guía para implementar acciones de prevención y control en México.

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Resumen: Objetivo: Estimar la magnitud de intoxicación por plomo (Pb) (≥5μg/dL en sangre) en niños de 1 a 4 años e identificar la contribución del uso de loza de barro vidriado con Pb (LBVPb) como fuente de exposición en los 32 estados de México. Material y métodos: Muestra de Pb en sangre (PbS) capilar de niños participantes en la Encuesta Nacional de Salud y Nutrición 2018-2019. Se estimó la prevalencia de intoxicación, su asociación con LBVPb y distribución nacional. Resultados: La prevalencia nacional de intoxicación fue 17.4%, lo cual representa 1.4 millones de niños. Esta prevalencia fue 30.7% entre usuarios de LBVPb y 11.8% entre no usuarios. En 17 estados la prevalencia de intoxicación es ≥10%; en 11 es ≥5-10% y en 4 es <5%. Conclusiones: Existe una distribución diferencial geográfica del problema; se confirma la asociación con LBVPb y se estima la contribución de otras fuentes de exposición. Esta información ofrece una guía para implementar acciones de prevención y control en México.

Abstract: Objective: To estimate de magnitude of Pb poisoning (≥5μg/dL blood) in 1-4 year old children and to identify the contribution of lead-glazed ceramics use (LGC) as a source of exposure in the 32 Mexican states. Materials and methods: Using the results from a sample of capillary blood lead (BPb) we estimated the prevalence of Pb poisoning, it's association with LGC and national distribution. Results: The national prevalence of Pb poisoning was 17.4% representing 1.4 million children. The prevalence was 30.7% among LGC users and 11.8% in non-users. In 17 states the prevalence of Pb poisoning was ≥10%, in 11 states between 5-10%, and in 4 states <5%. Conclusions: There is a geographic differential distribution of the problem; confirming the association with LGC and estimating the contribution of other Pb exposure sources. This information offers a guide to implement prevention and control actions in Mexico.

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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.

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 represen- tativa 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.

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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.

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Increasing human populations around the global coastline have caused extensive loss, degradation and fragmentation of coastal ecosystems, threatening the delivery of important ecosystem services1. As a result, alarming losses of mangrove, coral reef, seagrass, kelp forest and coastal marsh ecosystems have occurred1-6. However, owing to the difficulty of mapping intertidal areas globally, the distribution and status of tidal flats-one of the most extensive coastal ecosystems-remain unknown7. Here we present an analysis of over 700,000 satellite images that maps the global extent of and change in tidal flats over the course of 33 years (1984-2016). We find that tidal flats, defined as sand, rock or mud flats that undergo regular tidal inundation7, occupy at least 127,921 km2 (124,286-131,821 km2, 95% confidence interval). About 70% of the global extent of tidal flats is found in three continents (Asia (44% of total), North America (15.5% of total) and South America (11% of total)), with 49.2% being concentrated in just eight countries (Indonesia, China, Australia, the United States, Canada, India, Brazil and Myanmar). For regions with sufficient data to develop a consistent multi-decadal time series-which included East Asia, the Middle East and North America-we estimate that 16.02% (15.62-16.47%, 95% confidence interval) of tidal flats were lost between 1984 and 2016. Extensive degradation from coastal development1, reduced sediment delivery from major rivers8,9, sinking of riverine deltas8,10, increased coastal erosion and sea-level rise11 signal a continuing negative trajectory for tidal flat ecosystems around the world. Our high-spatial-resolution dataset delivers global maps of tidal flats, which substantially advances our understanding of the distribution, trajectory and status of these poorly known coastal ecosystems.

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Artisanal fisheries support millions of livelihoods worldwide, yet ineffective enforcement can allow for continued environmental degradation due to overexploitation. Here, we use spatial planning to design an enforcement strategy for a pre-existing spatial closure for artisanal fisheries considering climate variability, existing seasonal fishing closures, representative conservation targets and enforcement costs. We calculated enforcement cost in three ways, based on different assumptions about who could be responsible for monitoring the fishery. We applied this approach in the Patos Lagoon estuary (Brazil), where we found three important results. First, spatial priorities for enforcement were similar under different climate scenarios. Second, we found that the cost and percentage of area enforced varied among scenarios tested by the conservation planning analysis, with only a modest increase in budget needed to incorporate climate variability. Third, we found that spatial priorities for enforcement depend on whether enforcement is carried out by a central authority or by the community itself. Here, we demonstrated a method that can be used to efficiently design enforcement plans, resulting in the conservation of biodiversity and estuarine resources. Also, cost of enforcement can be potentially reduced when fishers are empowered to enforce management within their fishing grounds.

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OBJECTIVE:: To determine the prevalence of lead (Pb) poisoning at birth in Morelos, analyze its distribution by social marginalization level, and estimate the association with the use of lead glazed ceramics (LGC). MATERIALS AND METHODS:: Blood lead level (BLL) in umbilical cord was measured in a representative sample of 300 randomly selected births at the Morelos Health Services and state IMSS. RESULTS:: The prevalence of Pb poisoning at birth (BLL> 5µg/dL) was 14.7% (95%CI: 11.1, 19.3) and 22.2% (95%CI: 14.4, 32.5) in the most socially marginalized municipalities. 57.1% (95%CI: 51.3, 62.7) of the mothers used LGC during pregnancy, and the frequency of use was significantly associated with BLL. CONCLUSION:: This is the first study to document the proportion of newborns with Pb poisoning who are at risk of experiencing the related adverse effects. It is recommended to monitor BLL at birth and take action to reduce this exposure, especially in socially marginalized populations.

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Resumen: Objetivo: Determinar la prevalencia de intoxicación por plomo (IPb) al nacimiento en Morelos, analizar su distribución por nivel de marginación y estimar la asociación con el uso de barro vidriado (BV). Material y métodos: Se midió plomo en sangre (PbS) en cordón umbilical de una muestra representativa de 300 nacimientos seleccionados aleatoriamente de aquéllos atendidos por los Servicios de Salud de Morelos e IMSS estatal. Resultados: La prevalencia de IPb al nacimiento (PbS>5µg/dL) fue 14.7% (IC95%: 11.1, 19.3), y 22.2% (IC95%: 14.4, 32.5) en los municipios más marginados. 57.1% (IC95%: 51.3, 62.7) de las madres usaron BV durante el embarazo y la frecuencia de uso se asoció significativamente con PbS. Conclusión: Este es el primer estudio que documenta la proporción de recién nacidos con IPb que están en riesgo de sufrir los consecuentes efectos adversos. Se recomienda monitorear PbS al nacimiento y emprender acciones para reducir esta exposición, especialmente en poblaciones marginadas.

Abstract: Objective: To determine the prevalence of lead (Pb) poisoning at birth in Morelos, analyze its distribution by social marginalization level, and estimate the association with the use of lead glazed ceramics (LGC). Materials and methods: Blood lead level (BLL) in umbilical cord was measured in a representative sample of 300 randomly selected births at the Morelos Health Services and state IMSS. Results: The prevalence of Pb poisoning at birth (BLL> 5μg/dL) was 14.7% (95%CI: 11.1, 19.3) and 22.2% (95%CI: 14.4, 32.5) in the most socially marginalized municipalities. 57.1% (95%CI: 51.3, 62.7) of the mothers used LGC during pregnancy, and the frequency of use was significantly associated with BLL. Conclusion: This is the first study to document the proportion of newborns with Pb poisoning who are at risk of experiencing the related adverse effects. It is recommended to monitor BLL at birth and take action to reduce this exposure, especially in socially marginalized populations.

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BACKGROUND: Though lead contaminated waste sites have been widely researched in many high-income countries, their prevalence and associated health outcomes have not been well documented in low- and middle-income countries. METHODS: Using the well-established health metric disability-adjusted life year (DALY) and an exposure assessment method developed by Chatham-Stephens et al., we estimated the burden of disease resulting from exposure to lead at toxic waste sites in three Latin American countries in 2012: Argentina, Mexico and Uruguay. Toxic waste sites identified through Pure Earth's Toxic Sites Identification Program (TSIP) were screened for lead in both biological and environmental sample media. Estimates of cardiovascular disease incidence and other outcomes resulting from exposure to lead were utilized to estimate DALYs for each population at risk. RESULTS: Approximately 316,703 persons in three countries were at risk of exposure to pollutants at 129 unique sites identified through the TSIP database. Exposure to lead was estimated to result in between 51,432 and 115,042 DALYs, depending on the weighting factor used. The estimated burden of disease caused by exposure to lead in this analysis is comparable to that estimated for Parkinson's disease and bladder cancer in these countries. CONCLUSIONS: Lead continues to pose a significant public health risk in Argentina, Mexico, and Uruguay. The burden of disease in these three countries is comparable with other widely recognized public health challenges. Knowledge of the relatively high number of DALYs associated with lead exposure may be used to generate support and funding for the remediation of toxic waste sites in these countries and others.

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BACKGROUND: Although there has been success in reducing lead exposure with the phase-out of leaded gasoline, exposure to lead in Mexico continues to threaten the health of millions, much of which is from lead-based glazes used in pottery that leaches into food. OBJECTIVES: An extensive historical review and analysis of available data on blood lead levels in Mexican populations was conducted. We used a calculated geometric mean to evaluate the effect of lead on the pediatric burden of disease. METHODS: An extensive bibliographic search identified 83 published articles from 1978 to 2010 with blood lead level (BLL) data in Mexican populations representing 150 data points from more than 50,000 study participants. Values from these publications were categorized into various groupings. We then calculated the incidence of disease and disability-adjusted life-years resulting from these BLLs using the World Health Organization's burden of disease spreadsheets for mild mental retardation. RESULTS: Reviewing all relevant studies, the geometric means of Mexican BLLs in urban and rural areas were found to be 8.85 and 22.24 ug/dL, respectively. Since the phase-out of leaded gasoline, the mean in urban areas was found to be 5.36 ug/dL and the average in rural areas is expected to be much higher. The U.S. Centers for Disease Control and Prevention's (CDC) upper limit of blood lead in children under the age of 6 years is 5 ug/dL and the current U.S. average is 1.2 ug/dL. Our results indicate that more than 15% of the population will experience a decrement of more than 5 IQ points from lead exposure. The analysis also leads us to believe that lead is responsible for 820,000 disability-adjusted life-years for lead-induced mild mental retardation for children aged 0 to 4 years. CONCLUSION: Lead continues to threaten the health of millions and remains a significant cause of disability in Mexico. Additional interventions in reducing or managing lead-based ceramic glazes are necessary to protect the public health.

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BACKGROUND: In low- and middle-income countries (LMICs), chemical exposures in the environment due to hazardous waste sites and toxic pollutants are typically poorly documented and their health impacts insufficiently quantified. Furthermore, there often is only limited understanding of the health and environmental consequences of point source pollution problems, and little consensus on how to assess and rank them. The contributions of toxic environmental exposures to the global burden of disease are not well characterized. OBJECTIVES: The aim of this study was to describe the simple but effective approach taken by Blacksmith Institute's Toxic Sites Identification Program to quantify and rank toxic exposures in LMICs. This system is already in use at more than 3000 sites in 48 countries such as India, Indonesia, China, Ghana, Kenya, Tanzania, Peru, Bolivia, Argentina, Uruguay, Armenia, Azerbaijan, and Ukraine. METHODS: A hazard ranking system formula, the Blacksmith Index (BI), takes into account important factors such as the scale of the pollution source, the size of the population possibly affected, and the exposure pathways, and is designed for use reliably in low-resource settings by local personnel provided with limited training. FINDINGS: Four representative case studies are presented, with varying locations, populations, pollutants, and exposure pathways. The BI was successfully applied to assess the extent and severity of environmental pollution problems at these sites. CONCLUSIONS: The BI is a risk-ranking tool that provides direct and straightforward characterization, quantification, and prioritization of toxic pollution sites in settings where time, money, or resources are limited. It will be an important and useful tool for addressing toxic pollution problems in LMICs. Although the BI does not have the sophistication of the US Environmental Protection Agency's Hazard Ranking System, the case studies presented here document the effectiveness of the BI in the field, especially in low-resource settings. Understanding of the risks posed by toxic pollution sites helps assure better use of resources to manage sites and mitigate risks to public health. Quantification of these hazards is an important input to assessments of the global burden of disease.

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