Assessing the Risk of Phthalate Ester (PAE) Contamination in Soils and Crops Irrigated with Treated Sewage Effluent

Abstract

Waste/reclaimed irrigation water has been promoted due to water shortages in arid and semi-arid areas. However, this process may be one of the sources of phthalate esters (PAEs) in agricultural soils, and the potential risks of PAEs for soil ecosystems and human health have attracted considerable attention. A two-year (from October 2014 to October 2016) field experiment was conducted to assess the contamination risk of PAEs from reclaimed irrigation water in winter wheat (Triticum aestivum L.) and summer maize (Zea mays L.) fields on the North China Plain. Three types of irrigation water quality were arranged for each variety, including reclaimed water, groundwater, and a mixture of reclaimed water and groundwater (1:1, v/v). The results indicate that the concentrations of the 6 PAEs in topsoil ranged from 2.79 to 5.34 mg/kg at the time of crop harvest. There was no significant effect of reclaimed irrigation water on the concentrations of PAEs in the soil. Di-n-butyl phthalate (DnBP) and di (2-ethylhexyl) phthalate (DEHP) were the most abundant contaminants in all soil samples, accounting for 43.2%~68.7% and 27.1%~48.6%, respectively, of the 6 PAEs. The levels of dimethyl phthalate (DMP) and DnBP in all soil samples exceeded the allowable soil concentrations, but the levels were far below the recommended soil cleanup objectives. The grain yields of winter wheat and summer maize ranged from 4.35 to 7.1 t/ha and 1.03 to 6.46 t/ha, respectively. There were no significant effects of reclaimed water on the growth characteristics and grain yield of winter wheat (p > 0.05); however, the effect of reclaimed irrigation water on summer maize was influenced by climate. The concentrations of the 6 PAEs in wheat grain and maize grain ranged from 1.03 to 4.05 mg/kg and from 0.37 to 3.29 mg/kg, respectively. For the same variety, there was no significant difference in the concentrations of the 6 PAEs in cereal grains among different treatments (p > 0.05). DEHP and DnBP were the most abundant components in most crop samples, accounting for 31.6%~77.9% and 21.1%~64.7%, respectively, of the 6 PAEs. The concentrations of the PAEs, DnBP and DEHP in cereal grains were lower than those in the reference doses. The BCFs of the 6 PAEs and of each PAE in cereal grains were 0.43~1.25 and 0.33~35.75, respectively. The BCFs of butyl benzyl phthalate (BBP) were the highest (1.41~35.75), followed by DMP and DEHP. There were almost no significant differences in the BCFs of each PAE among the three treatments. The total carcinogenic risks of PAEs were 2.82 × 10 −5 for adults and 1.81 × 10 −5 for children. The total non-carcinogenic risks of PAEs were 3.37 × 10 −1 for adults and 7.98 × 10 −1 for children. DHEP was the dominant contributor to both risks, and the intake of cereals was the main exposure pathway for the two risks. In conclusion, there were no significant effects of reclaimed irrigation water on the concentrations of PAEs in soil and cereal grains compared with groundwater irrigation, and the human health risks were within ...

Major contaminants of emerging concern in soils: a perspective on potential health risks

“…3a and b ). 160 Often, there are seasonal variations in the deposition of phthalates in the soils. For instance, the concentration of phthalates in topsoils at winter wheat harvest was significantly higher than those at the summer maize harvest.…”

“…For instance, the concentration of phthalates in topsoils at winter wheat harvest was significantly higher than those at the summer maize harvest. 160 Implications are that wet deposition scavenges the phthalates easily from their source materials, subscribing significantly to their transport into soil media. Phthalates can easily reach the agricultural soils by applying agricultural plastic films, irrigation water, sewage sludge, biosolids, and fertilizers.…”

Uptake of a plasticizer (di-n-butyl phthalate) impacts the biochemical and physiological responses of barley

“…Likewise, higher values of phthalates’ AF were observed in wheat and maize ( Tan et al 2018 ). In another study, AF was calculated for six phthalates in the grains of Triticum aestivum and Zea mays that were observed to vary from 0.33 to 33.75 ( Li et al, 2018b ). DBP has been reported to accumulate and translocate like other lipophilic pollutants.…”

Presence and Natural Treatment of Organic Micropollutants and their Risks after 100 Years of Incidental Water Reuse in Agricultural Irrigation

“…These scenarios are different from those that actually occur in the Mezquital Valley but are undoubtedly important references to consider in future research, which mainly concern factors that influence the transportation and observed destination of EDCs and analysis in soil, roots, leaves, and edible crops [55]. Yet, there are undoubtedly important references to consider in future research studies, which are mainly regarding the factors influencing the transport and observed destination of EDCs [56,57], in an analytical experience for detection in soil, roots, leaves, and part of the edible cultivation [52], as well as in the risk assessment associated with the presence of EDCs in crops in the region [49,58].…”

“…Phthalates have been extensively investigated in different agricultural areas of the world. They have been observed in soil and crops, and, in many cases, in concentrations within the acceptable limits of risk for human consumption [49]. Lastly, carbamazepine, which is among the extensive list of drugs reported in the literature, is possibly the most frequently studied due to its characteristics of persistence in the environment.…”