Changes in Blood Lead Levels Associated with Use of Chloramines in Water Treatment Systems

Abstract

BackgroundMore municipal water treatment plants are using chloramines as a disinfectant in order to reduce carcinogenic by-products. In some instances, this has coincided with an increase in lead levels in drinking water in those systems. Lead in drinking water can be a significant health risk.ObjectivesWe sought to test the potential effect of switching to chloramines for disinfection in water treatment systems on childhood blood lead levels using data from Wayne County, located in the central Coastal Plain of North Carolina.MethodsWe constructed a unified geographic information system (GIS) that links blood lead screening data with age of housing, drinking water source, and census data for 7,270 records. The data were analyzed using both exploratory methods and more formal multivariate techniques.ResultsThe analysis indicates that the change to chloramine disinfection may lead to an increase in blood lead levels, the impact of which is progressively mitigated in newer housing.ConclusionsIntroducing chloramines to reduce carcinogenic by-products may increase exposure to lead in drinking water. Our research provides guidance on adjustments in the local childhood lead poisoning prevention program that should accompany changes in water treatment. As similar research is conducted in other areas, and the underlying environmental chemistry is clarified, water treatment strategies can be optimized across the multiple objectives that municipalities face in providing high quality drinking water to local residents.

Elevated Blood Lead Levels and Reading Readiness at the Start of Kindergarten

“…Other studies [3][4][5] have reported that the change in the BLL-reading score relationship is not linear. Like Miranda et al' s 8 observations of end-of-grade test scores, the magnitude of the difference in fall PALS-K scores associated with lead exposure in our study was similar to the difference associated with eligibility for free and reduced lunch, a measure of low SES.…”

“…2 Crosssectional and longitudinal studies have revealed significant effects of lead exposure on learning with the use of standardized school tests and functional measures of school performance, including reading and math test scores, reading at grade level, and graduation from high school. [3][4][5][6][7][8] This evidence is reflected in Centers for Disease Control and Prevention' s recent establishment of a population-based reference value to target children with blood lead levels (BLLs) above the 97.5th percentile, which is currently a BLL of 5 mg/dL. 9 Learning to read is critical to the entire process of formal education.…”

Exploring Childhood Lead Exposure through GIS: A Review of the Recent Literature

“…Public health departments recognized the advantages of GIS in screening, exposure prediction, and mapping cases. Using BLL data for lead poisoning, an increasing number of GIS-based ecological studies have identified risk factors as socioeconomic status (SES) [9][10][11][12][13][14][15][16][17][18]21], year built of housing [7][8][9][10][11]13,[15][16][17][18]20,21,23,28], race [11,13,14,16,17,21,23,27,28] and ethnicity [15,16,18].…”

“…At the data preparation stage, address geocoding is the most used tool to transfer tabular data sets, such as screened children addresses, into GIS [7][8][9][10][11][12][13][14][15][16][17][18][19]23]. Various GIS functions were used for multivariate mapping of BLLs and risk factors in a limited custom such as linking SES data with screened data records [49,50], map overlays [51,52], distance calculations [53], and hyperlinks to demolishing sites' photos and city maps for mapping dust-fall lead loadings [54].…”

How Do Changes in Water Quality and Dialysate Composition Affect Clinical Outcomes?

“…Water companies are continuously reviewing their water treatment processes, and this may require review of the technology in use in dialysis units. For example, chlorine is being replaced by chloramines and monochloramine can increase the amount of bioavailable lead by interacting with domestic water piping [7] .…”