Concentrations of polycyclic aromatic hydrocarbons in New York City community garden soils: Potential sources and influential factors

Abstract

A total of 69 soil samples from 20 community gardens in New York City (New York, USA) were collected and analyzed for 23 polycyclic aromatic hydrocarbons (PAHs) and black carbon. For each garden, samples were collected from nongrowing areas (non-bed) and from vegetable-growing beds, including beds with and without visible sources of PAHs. The sum of the US Environmental Protection Agency's 16 priority PAHs ranged up to 150 mg/kg, and the median (5.4 mg/kg) and mean (14.2 mg/kg) were similar to those previously reported for urban areas in the northeast United States. Isomer ratios indicated that the main sources of PAHs were petroleum, coal, and wood combustion. The PAH concentrations were significantly and positively associated with black carbon and with modeled air PAH concentrations, suggesting a consistent relationship between historical deposition of atmospheric carbon-adsorbed PAHs and current PAH soil concentrations. Median PAH soil concentration from non-bed areas was higher (7.4 mg/kg) than median concentration from beds in the same garden (4.0 mg/kg), and significantly higher than the median from beds without visible sources of PAHs (3.5 mg/kg). Median PAH concentration in beds from gardens with records of soil amendments was 58% lower compared with beds from gardens without those records. These results suggest that gardening practices in garden beds without visible sources of PAHs contribute to reduce PAH soil concentrations.

Influence of Air Pollution and Soil Contamination on the Contents of Polycyclic Aromatic Hydrocarbons (PAHs) in Vegetables Grown in Urban Gardens of Sao Paulo, Brazil

“…The contents of organic and black carbon in soil were not analysed. The results found by Marquez -Bravo et al (2016) in New York indicate that soil PAHs are positively associated with air-modelled particulate PAHs, suggesting that atmospheric deposition, rather than onsite sources, may be a source of PAHs to soils. We analysed only 2 leafy vegetables, so our results cannot be generalized to other vegetables.…”

“…The concentrations of PAHs in soil in urban centres usually reflect past contributions from point or diffuse sources, including past land use and disposal practices (Marquez-Bravo et al, 2016). The ranges of concentrations of the 16 PAHs identified by the US EPA as priority pollutants found in the soils of New York, USA; Bitterfeld-Wolfen, Germany; Guangzhou, China; Shanghai, China; Kathmandu, Nepal; Panipat, India; and Isfahan, Iran were 0.1-149.5 mg kg −1 (Marquez-Bravo et al, 2016); 0.03-7.0 µg kg −1 (Wennrich et al, 2002); 0.04-3.1 mg kg −1 (Chen et al, 2005); 0.08-7.22 mg kg −1 (Wang et al, 2013); 0.17-0.68 mg kg −1 (Aichner et al, 2007); 0.13-0.17 mg kg −1 (Tuteja et al, 2011);and 0.06-11.73 mg kg −1 (Moore et al, 2015), respectively.…”

“…The ranges of concentrations of the 16 PAHs identified by the US EPA as priority pollutants found in the soils of New York, USA; Bitterfeld-Wolfen, Germany; Guangzhou, China; Shanghai, China; Kathmandu, Nepal; Panipat, India; and Isfahan, Iran were 0.1-149.5 mg kg −1 (Marquez-Bravo et al, 2016); 0.03-7.0 µg kg −1 (Wennrich et al, 2002); 0.04-3.1 mg kg −1 (Chen et al, 2005); 0.08-7.22 mg kg −1 (Wang et al, 2013); 0.17-0.68 mg kg −1 (Aichner et al, 2007); 0.13-0.17 mg kg −1 (Tuteja et al, 2011);and 0.06-11.73 mg kg −1 (Moore et al, 2015), respectively. To our knowledge, only one study has analysed the concentrations of PAHs on soil within the urban area of Sao Paulo, in a remnant part of the Atlantic Forest, located in the neighborhood of a large industrial area (Bourotte et al, 2009).…”

“…None of the garden beds were installed on asphalt or had creosote-treated timber sidewalls. The mean Euclidean distance from heavily trafficked roads was 130 m; one garden was located less than 15 m from a road (Marquez-Bravo et al, 2016). One garden was located within 40 m of a local potential source of petrogenic PAHs ( Table 1).…”

“…Very few studies have been conducted regarding the concentrations of PAHs in the vegetables and soil beds of UCGs (Marquez-Bravo et al, 2016), and no studies have addressed the influence of air pollution on the contents of PAHs in vegetables grown in UCGs.…”