Urban community gardens have increased in prevalence as a means to generate fresh fruits and vegetables, including in areas lacking access to healthy food options. However, urban soils may have high levels of toxic heavy metals, including lead and cadmium and the metalloid arsenic, which can lead to severe health risks. In this study, fruit and vegetable samples grown at an urban community garden in southeastern San Diego, the Ocean View Growing Grounds, were sampled repeatedly over a four‐year time period in order to measure potential contamination of toxic heavy metals and metalloids and to develop solutions for this problem. Metal nutrient, heavy metal, and metalloid concentrations were monitored in the leaf and fruit tissues of fruit trees over the sampling period. Several of the fruit trees showed uptake of lead in the leaf samples, with Black Mission fig measuring 0.843–1.531 mg/kg dry weight and Mexican Lime measuring 1.103–1.522 mg/kg dry weight over the sampling period. Vegetables that were grown directly in the ground at this community garden and surrounding areas showed arsenic, 0.80 + 0.073 mg/kg dry weight for Swiss chard, and lead, 0.84 ± 0.404 mg/kg dry weight for strawberries, in their edible tissues. The subsequent introduction of raised beds with uncontaminated soil is described, which eliminated any detectable heavy metal or metalloid contamination in these crops during the monitoring period. Recommendations for facilitating the monitoring of edible tissues and for reducing risk are discussed, including introduction of raised beds and collaborations with local universities and research groups.

中文翻译：

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粮食作物中有毒重金属和砷积累的监测和缓解：城市社区花园的案例研究。


城市社区花园作为生产新鲜水果和蔬菜的手段越来越普遍，包括在缺乏健康食品选择的地区。然而，城市土壤可能含有大量有毒重金属，包括铅、镉和准金属砷，这可能会导致严重的健康风险。在这项研究中，在四年的时间里对圣地亚哥东南部城市社区花园（即海景种植地）种植的水果和蔬菜样本进行了反复采样，以测量有毒重金属和类金属的潜在污染，并开发这个问题的解决方案。在采样期间监测果树叶子和果实组织中的金属养分、重金属和类金属浓度。一些果树的叶子样本中显示出铅的吸收，在采样期间，黑使命无花果的干重测量为 0.843–1.531 毫克/千克，墨西哥青柠的测量为 1.103–1.522 毫克/千克干重。该社区花园及周边地区直接种植的蔬菜的可食用组织中，砷含量为 0.80 ± 0.073 毫克/千克干重，瑞士甜菜含量为 0.84 ± 0.404 毫克/千克干重，铅含量为 0.84 ± 0.404 毫克/千克干重。随后介绍了采用未受污染土壤的高位床，消除了监测期间这些作物中任何可检测到的重金属或类金属污染。讨论了促进可食用组织监测和降低风险的建议，包括引入高架床以及与当地大学和研究小组的合作。