Lead contamination of public drinking water and academic achievements among children in Massachusetts: a panel study

Background Public drinking water can be an important source exposure to lead, which can affect children’s cognitive development and academic performance. Few studies have looked at the impact of lead exposures from community water supplies or their impact on school achievements. We examined the association between annual community water lead levels (WLLs) and children’s academic performances at the school district level. Methods We matched the 90th percentile WLLs with the grade 3–8 standardized test scores from the Stanford Education Data Archive on Geographic School Districts by geographic location and year. We used multivariate linear regression and adjusted for urbanicity, race, socioeconomic characteristics, school district, grade, and year. We also explored potential effect measure modifications and lag effects. Results After adjusting for potential confounders, a 5 μg/L increase in 90th percentile WLLs in a GSD was associated with a 0.00684 [0.00021, 0.01348] standard deviation decrease in the average math test score in the same year. No association was found for English Language Arts. Conclusions We found an association between the annual fluctuation of WLLs and math test scores in Massachusetts school districts, after adjusting for confounding by urbanicity, race, socioeconomic factors, school district, grade, and year. The implications of a detectable effect of WLLs on academic performance even at the modest levels evident in MA are significant and timely. Persistent efforts should be made to further reduce lead in drinking water.

Electrochemical Deposition of Lead for Water Quality Sensing

Lead contamination in drinking water can pose serious health risks to humans, and can often go undetected as a result of corrosion of lead infrastructure installed in buildings constructed prior to 1986. Thus, there is an unmet need for timely, cost-effective, and onsite monitoring of lead in drinking water. Here, we have designed a four-electrode system to reliably respond to electrodeposited lead oxide that provides a near real-time indication of lead presence. To better understand this detection mechanism, we investigated the temporal and spatial electrochemical deposition of lead using potential response data, scanning electron microscopy (SEM), fractal dimension (fD), and COMSOL Multiphysics® finite element analysis. Our results suggest that the deposition of lead oxide on the sensor is diffusion limited. Such fundamental understanding of the detection mechanism is critical to improve and shorten the detection time of the sensor. We used this information to improve the detection time and reliability of the signal by reducing the electrode gap distance and agitating the solution. This study provides a path for further optimization of a continuous electrochemical sensor for onsite monitoring of lead in drinking water.

Full Lead Service Line Replacement: A Case Study of Equity in Environmental Remediation

In the U.S., approximately 9.3 million lead service lines (LSLs) account for most lead contamination of drinking water. As the commitment to replace LSLs with safer materials grows, empirical evidence is needed to understand which households are benefitting most from current replacement practices. This exploratory study analyzes factors predictive of whether an LSL was replaced fully (from water main to premise) or partially (only the portion on public property). Conventional ordinary least squares, negative binomial, and geographically weighted regression models are used to test the hypothesis that full lead service line replacements (LSLRs) were less common in lower-income, higher-minority neighborhoods under a cost-sharing program design in Washington, D.C. between 2009 and 2018. The study finds supportive evidence that household income is a major predictor of full replacement prevalence, with race also showing significance in some analyses. These findings highlight the need for further research into patterns of full versus partial LSLR across the U.S. and may inform future decisions about LSLR policy and program design.

Effect of Exterior Home Renovation on Community Lead Hazards: A Pilot Study in South Bend, Indiana

Communities across the US face challenges from legacy lead contamination. In South Bend, Indiana, over 68,000 homes were built before 1978, and most contain leaded paint. When these homes are repainted, repaired, or renovated, failure to use lead-safe practices can contaminate the surrounding soil with lead paint flakes and dust. In this study, we used X-ray fluorescence (XRF) to measure soil lead levels surrounding a home with exterior leaded paint (about 10% Pb w/w) after it was repainted in fall of 2019. The painted wooden exterior was prepared for painting by dry scraping without the use of tarps or plastic barriers. A total of 220 soil samples were collected from the home and its immediate neighbors, and an additional 102 samples were collected from 34 homes in the same neighborhood. The median lead level in dripline soil samples across the neighborhood was 434 ppm, but in the recently repainted house, the median soil lead was 1808.9 ppm, and it was 1,346.4 ppm in the four neighboring homes. The repainted house and its four neighbors were mulched by covering all bare soil to a 4-6 inch depth with chipped wood mulch. Two months later, another 100 soil samples were collected and analyzed. The surface lead level around the target house dropped to 13.8 ppm, showing that mulching is an effective strategy for interim control of high soil lead levels.

Reduction in Blood Lead Concentration in Children across the Republic of Georgia following Interventions to Address Widespread Exceedance of Reference Value in 2019

In recent years, reports of lead contamination have dramatically increased in Georgia. Given concerns about the exposure of children to lead (Pb), the National Multiple Indicator Cluster Survey (MICS-2018) included a blood sampling component. The results showed that 41% of the children that participated had blood Pb levels (BLL) ≥ 5 µg/dL and that BLL in children living in Western Georgia were higher than those in Eastern regions. In response to these findings, NCDC implemented written and verbal advice to the families of children who participated in the MICS-2018 on how to reduce Pb exposure. From August 2019 onwards, the state program of clinical follow-up was implemented. The design of this study was a longitudinal study. The intervention of interest was the public health advice and medical follow-up, and the outcome was defined as the difference in BLL between the MICS-2018 survey and the state program follow-up. We observed a significant overall reduction in median BLL between MICS-2018 and state program follow-up in both August 2019 and the latest results (until December 2019). However, we did not observe any significant further reduction between August and the most recent BLL results. In the Georgian setting, written and verbal communication targeting individual households, alongside home visits to the most exposed, effectively reduced BLL in children.

Addressing Risks of Lead in Water and Soil

One of the most widespread environmental health hazards in the United States remains exposure to the harmful neurotoxin lead. So much lead remains in the urban environment that it is not unusual to find neighborhoods where more than 10% of children exhibit harmful levels of lead, compared to the national average of about 1%. To overcome this challenge, a partnership between IUPUI researchers and faith organizations in Indianapolis is taking aim at the risk of household lead contamination by providing residents the tools they need to protect against it. The community-driven science aspect of this project is intentional—not only will the individuals who participate benefit directly, but the resulting data will also play a role in keeping communities safer more broadly.

Assessment of Responses of Common Carp, Cyprinus carpio, Exposed to Sub-Lethal Concentrations of Lead, by Molecular and Mucosal Biomarkers

Heavy metals are one of the most persistent pollutants in waters, and molecular biomarkers as bioindicators could uncover early warning signals of stress suffered by organisms exposed to these pollutants. This research was conducted to explore the impact of lead contaminant on expression levels of hsp70 gene as well as protein pattern and innate immune indicators of skin mucus in Common carp as a biological model. The fish were exposed to different concentrations of Pb(NO3)2 as a source of lead (0, 7.875, 15.75, and 31.5 mg/L of lead) for 14 days. After the completion of the experiment, the liver and gill tissue plus mucus samples were collected from the fish. Next, the effects of exposure to sublethal doses of lead were investigated on expression levels of hsp70 gene, protein pattern, and innate immune indicators of skin mucus. The results indicated that the expression level of hsp70 gene significantly increased (at 7.5% & 30% LC50) in the liver tissue compared to the control group (P<0.05). The protein pattern of treatment samples was different from that of the control group. Also, in the mucus innate immune parameters, the levels of alkaline phosphatase increased significantly at high concentrations of lead contamination in comparison with the control group (P<0.05). The protein levels first revealed an ascending trend (P<0.05), and then a descending trend (at 30% LC50), though it was not a significant downward trend compared with the control group (P>0.05). The results suggested that these physiological indicators in Cyprinus carpio could be used as molecular and mucosal biomarkers for ecotoxicological studies.