RESUMEN
Gaps in the United States Environmental Protection Agency (US EPA) Lead and Copper Rule (LCR) leave some consumers and their pets vulnerable to high cuprosolvency in drinking water. This study seeks to help proactive utilities who wish to mitigate cuprosolvency problems through the addition of orthophosphate corrosion inhibitors. The minimum doses of orthophosphate necessary to achieve acceptable cuprosolvency in relatively new copper pipe were estimated as a function of alkalinity via linear regressions for the 90th, 95th, and 100th percentile copper tube segments (R2 > 0.98, n = 4). Orthophosphate was very effective at reducing cuprosolvency in the short term but, in some cases, resulted in higher long-term copper concentrations than the corresponding condition without orthophosphate. Alternatives to predicting "long-term" results for copper tubes using simpler bench tests starting with fresh Cu(OH)2 solids showed promise but would require further vetting to overcome limitations such as maintaining water chemistry and orthophosphate residuals and to ensure comparability to results using copper tube.
Asunto(s)
Agua Potable , Contaminantes Químicos del Agua , Estados Unidos , Cobre/análisis , Fosfatos , Abastecimiento de Agua , CorrosiónRESUMEN
Lead in drinking water remains a significant human health risk. At-home lead in water test kits could provide consumers with a convenient and affordable option to evaluate this risk, but their accuracy and reliability is uncertain. This study examined the ability of at-home lead test kits to detect varying concentrations of dissolved and particulate lead in drinking water. Sixteen brands representing four test kit types (binary color, binary strip, colorimetric vial, and color strip) were identified. Most kits (12 of 16 brands) were not suitable for drinking water analysis, with lead detection limits of 5-20 mg/L. Binary strips detected dissolved lead at drinking water-relevant levels but failed to detect particulate lead. Household acids (lemon juice and vinegar) improved the strip's ability to detect lead by dissolving some of the lead particulates to the point soluble lead exceeded 15 µg/L. These results illustrate the applications of at-home testing kits for drinking water analysis, highlight limitations and areas for possible improvement, and put forth a testing protocol by which new at-home lead test kits can be judged.
Asunto(s)
Agua Potable , Contaminantes Químicos del Agua , Humanos , Reproducibilidad de los Resultados , Contaminantes Químicos del Agua/análisis , Abastecimiento de AguaRESUMEN
The pervasiveness of lead in drinking water poses a significant public health threat, which can be reduced by implementing preventive measures. However, the causes of elevated lead in water and the benefits of lead in water avoidance strategies are often misunderstood. Based on experiences in the United States, this paper describes an oversimplified 'lead in water equation' to explain key variables controlling the presence of lead in drinking water to better inform public health practitioners, government officials, utility personnel, and concerned residents. We illustrate the application of the equation in Flint, Michigan and explore the primary household-level water lead avoidance strategies recommended during the crisis, including flushing, filtration, bottled water use, and lead pipe removal. In addition to lead reduction, strategies are evaluated based on costs and limitations. While these lead avoidance strategies will reduce water lead to some degree, the costs, limitations, and effectiveness of these strategies will be site- and event-specific. This paper presents a simplified approach to communicate key factors which must be considered to effectively reduce waterborne lead exposures for a wide range of decision makers.
Asunto(s)
Agua Potable , Plomo/análisis , Contaminantes Químicos del Agua/análisis , Michigan , Salud Pública , Estados Unidos , Abastecimiento de AguaRESUMEN
MAIN OBJECTIVE: The objective of this study is to describe the use of emergent head computed tomography (CT) in young children and ask in which circumstances scans contributed to immediate management. METHODS: We reviewed electronic records of children, aged 1 month through 6 years, who received a head CT at a large suburban emergency department between February 2008 and February 2009. Age, sex, chief complaint, history, physical examination, indication for and results of head CT, red flags in history or physical examination, final disposition, and number of head CT scans performed to date were recorded. Abnormalities on CT scans were classified as significant or incidental, and subsequent interventions were documented. RESULTS: Emergent head CTs were performed on 394 children. The most common indications were trauma, 65%; seizure, 11%; and headache, 6%. Computed tomographic abnormalities were found in 40% (154 children): 32 significant findings,104 incidental findings, and 22 preexisting abnormalities. Four children with significant findings required immediate intervention. They all had red flags in both history and physical examination, and 3 of 4 children had known preexisting pathology; 1 child had nonaccidental trauma. Only 1 child had a significantly abnormal CT with no identifiable red flags; this child was admitted for observation and was discharged within 24 hours. Approximately a third of children had no readily identifiable red flag for the CT scans that they received. Of note, 20% of the young children had received more than 1 head CT scan to date, and 6% had between 6 and 20 scans. CONCLUSIONS: Every child in this sample who required emergency intervention had red flags on history and physical examination. The 35% of CT scans performed in young children without red flags did not contribute usefully to their acute management.