Abstract

Background:

Emerging evidence suggests social, health, environmental, and economic benefits of urban agriculture (UA). However, limited work has characterized the risks from metal contaminant exposures faced by urban growers and consumers of urban-grown produce.

Objectives:

We aimed to answer community-driven questions about the safety of UA and the consumption of urban-grown produce by measuring concentrations of nine metals in the soil, irrigation water, and urban-grown produce across urban farms and gardens in Baltimore, Maryland.

Methods:

We measured concentrations of 6 nonessential [arsenic (As), barium (Ba), cadmium (Cd), chromium (Cr), lead (Pb), nickel (Ni)] and three essential [copper (Cu), manganese (Mn), zinc (Zn)] metals in soil, irrigation water, and 13 types of urban-grown produce collected from 104 UA sites. We compared measured concentrations to existing public health guidelines and analyzed relationships between urban soil and produce concentrations. In the absence of guidelines for metals in produce, we compared metals concentrations in urban-grown produce with those in produce purchased from farmers markets and grocery stores (both conventionally grown and U.S. Department of Agriculture–certified organic).

Results:

Mean concentrations of all measured metals in irrigation water were below public health guidelines. Mean concentrations of nonessential metals in growing area soils were below public health guidelines for Ba, Cd, Pb, and Ni and at or below background for As and Cr. Though we observed a few statistically significant differences in concentrations between urban and nonurban produce items for some combinations, no consistent or discernable patterns emerged.

Discussion:

Screening soils for heavy metals is a critical best practice for urban growers. Given limitations in existing public health guidelines for metals in soil, irrigation water, and produce, additional exposure assessment is necessary to quantify potential human health risks associated with exposure to nonessential metals when engaging in UA and consuming urban-grown produce. Conversely, the potential health benefits of consuming essential metals in urban-grown produce also merit further research. https://doi.org/10.1289/EHP9431

中文翻译：

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安全的城市收获研究：社区驱动的对马里兰州巴尔的摩城市农场和花园中的土壤、灌溉水和农产品中的金属进行横截面评估

摘要

背景：

新出现的证据表明都市农业 (UA) 的社会、健康、环境和经济效益。然而，有限的工作已经描述了城市种植者和城市种植农产品消费者面临的金属污染物暴露风险。

目标：

我们旨在通过测量马里兰州巴尔的摩城市农场和花园中土壤、灌溉用水和城市种植的农产品中九种金属的浓度来回答社区驱动的关于 UA 安全性和城市种植农产品消费的问题。

方法：

我们测量了 6 种非必需元素 [砷 (As)、钡 (Ba)、镉 (Cd)、铬 (Cr)、铅 (Pb)、镍 (Ni)] 和三种必需元素 [铜 (Cu)、锰 (Mn) 的浓度, 锌 (Zn)] 金属在土壤、灌溉用水和从 104 个 UA 站点收集的 13 种城市种植的农产品。我们将测量的浓度与现有的公共卫生指南进行了比较，并分析了城市土壤与农产品浓度之间的关系。在没有关于农产品中金属的指导方针的情况下，我们将城市种植的农产品中的金属浓度与从农贸市场和杂货店购买的农产品（传统种植和美国农业部认证的有机产品）中的金属浓度进行了比较。

结果：

灌溉水中所有测量金属的平均浓度均低于公共卫生准则。Ba、Cd、Pb 和 Ni 的生长区土壤中非必需金属的平均浓度低于公共卫生准则，而 As 和 Cr 则处于或低于本底值。尽管我们观察到某些组合的城市和非城市农产品浓度在统计上存在显着差异，但没有出现一致或可辨别的模式。

讨论：

筛选土壤中的重金属是城市种植者的关键最佳实践。鉴于现有关于土壤、灌溉水和农产品中金属的公共卫生指南存在局限性，因此有必要进行额外的暴露评估，以量化在从事 UA 和消费城市种植的农产品时与接触非必需金属相关的潜在人类健康风险。相反，在城市种植的农产品中消费必需金属的潜在健康益处也值得进一步研究。https://doi.org/10.1289/EHP9431