Impact of biosolids and wastewater effluent application to agricultural land on steroidal hormone content in lettuce plants

Abstract

One of the major concerns for human health in the past decade is the potential dangers posed by increased concentrations of steroidal hormones in soils and water. These hormones are considered to be endocrine disrupting compounds (EDCs), which may harm human health when exposed to high concentrations, or in the case of long term exposure to lower concentrations. In a 3year study, two steroids, estrone and testosterone, were measured in lettuce plants irrigated with wastewater effluents and freshwater and treated with several types of biosolids.The relative contribution of the different factors, mainly irrigation water and biosolids, to the hormone levels in the lettuce plants was determined. It was found that irrigation water, which contained significant amounts of hormones, had the most substantial effect, whereas biosolids had only minor influence on hormone levels in the lettuce.The hormone levels in the plants were compared to the FDA recommendation for daily consumption in food, and were found to exceed the recommended level (when consumed by a typical individual), and therefore could have negative physiological impacts.Overall this study shows that biosolids have little effect on hormone uptake by lettuce, and it emphasizes the negative impact of irrigation water on these levels, which is of concern to public health.