Spatial distribution of lead concentrations in urban surface soils of New Orleans, Louisiana USA

Abstract

Immediately following hurricane Katrina concern was raised over the environmental impact of floodwaters on the city of New Orleans, especially in regard to human health. Several studies were conducted to determine the actual contaminant distribution throughout the city and surrounding wetlands by analyzing soil, sediment, and water for a variety of contaminants including organics, inorganics, and biologics. Preliminary investigations by The Institute of Environmental and Human Health at Texas Tech University concluded that soils and sediments contained pesticides, semi-volatiles, and metals, specifically arsenic, iron, and lead, at concentrations that could pose a significant risk to human health. Additional studies on New Orleans floodwaters revealed similar constituents as well as compounds commonly found in gasoline. More recently, it has been revealed that lead (Pb), arsenic, and vanadium are found intermittently throughout the city at concentrations greater than the human health soil screening levels (HHSSLs) of 400, 22 (non-cancer endpoint) and 390 μg/g, respectively. Of these, Pb appears to present the greatest exposure hazard to humans as a result of its extensive distribution in city soils. In this study, we spatially evaluated Pb concentrations across greater New Orleans surface soils. We established 128 sampling sites throughout New Orleans at approximately half-mile intervals. A soil sample was collected at each site and analyzed for Pb by ICP-AES. Soils from 19 (15%) of the sites had Pb concentrations exceeding the HHSSL threshold of 400 μg/g. It was determined that the highest concentrations of Pb were found in the south and west portions of the city. Pb concentrations found throughout New Orleans in this study were then incorporated into a geographic information system to create a spatial distribution model that can be further used to predict Pb exposure to humans in the city.

Chemical contamination of soils in the New York City area following Hurricane Sandy

“…The average concentration of arsenic was 9 mg/kg (median 6 mg/kg) with a standard deviation of 13 mg/ kg. Based on these data and the known heterogeneity of urban soils (Abel et al 2010), our concentrations appear to be in reasonable agreement with previously reported values.…”

“…One month after flood waters had receded contamination of arsenic and vanadium compared to EPA Region 6, background soil levels were found (Su et al 2008). Several groups found elevated lead in soils collected after Katrina (Adams et al 2007;Abel et al 2010;Presley et al 2006;Cobb et al 2006), and some also found cocontaminants such as arsenic and semi-volatile organic compounds (Abel et al 2010;Presley et al 2006;Cobb et al 2006). Rabito et al (2012) discovered that 27 % of samples from households with bare soil contained lead levels exceeding 1200 lg/g after the hurricane; median lead values were significantly higher than those obtained before Hurricane Katrina.…”

The Dublin SURGE Project: geochemical baseline for heavy metals in topsoils and spatial correlation with historical industry in Dublin, Ireland

“…2c), the highest concentrations of Pb occur in the oldest inner city parts of Dublin, with levels declining concentrically with distance from the city centre. Other urban soil Pb studies from around the world have clearly demonstrated a similar pattern (including Abel et al 2010; Haugland et al 2008; and studies cited in Davies 1990). According to our chosen scale breaks, the highest 10 % predictions (predominantly in the city centre) can range from just under 200 mg kg −1 up to highs of over 470 mg kg −1 .…”

“…Ireland does not yet have dedicated contaminated land guidance derived exclusively for the Irish environment. For contaminations like Pb, there is no consensus worldwide on the protective threshold for human health in soil (Abel et al 2010), and therefore, it is important to understand local conditions in assessing risks to human health from soil contaminants.…”

Health Effects of Coastal Storms and Flooding in Urban Areas: A Review and Vulnerability Assessment

“…Following Hurricane Katrina, hazardous substances such as volatile organic compounds (VOCs), lead, and arsenic were detected in the air, soil, and sediment samples. No health effects have been directly observed in a storm-specific context [54–59]. However, the potential for a toxic release of hazardous substances after a storm exists [55–57].…”