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BACKGROUND: Toxic heavy metals (THMs) cause severe environmental hazards and threaten human health through various consumption of food stuff. However, little is known of THMs in chestnuts. In this study, the risk assessment and prediction of THMs [lead (Pb), arsenic (As), chromium (Cr), cadmium (Cd) and mercury (Hg)] in chestnuts and growth soils from China were investigated. RESULTS: The main detected THMs in chestnuts and growth soils were As and Cd. The total pollution levels of the five THMs (Nemerow pollution indexes, NPIs) were 0.062 and 1.06, respectively. The dietary risks for children were higher than those of adults, especially short‐term non‐carcinogenic risk. The main combined risks from the relationships between THMs were Pb‐Cr (r = 0.85, P < 0.01) in chestnuts and Pb‐As (r = 0.59, P < 0.01) in growth soils. The risk source was found to be the uptake effect of THMs from soil to chestnut, with the highest bioaccumulation factors (BCFs) of Cd (0.254). Several comprehensive risk models were established with the highest coefficient of determination (R2) of 0.79. In addition, the main contribution rates of different soil parameters to comprehensive risk of THMs uptake were 49.8% (Cd), 23.4% (pH), 13.8% (Cr) and 13.0% (organic carbon). CONCLUSION: The total pollution levels of THMs fell outside of the safety domain in growth soils. Furthermore, more attention needs to be paid to Cd pollution owing to its low environment background value and high accumulation ability. Three main soil parameters (Cr content, pH, organic carbon) played important roles in the formations and accumulations of THMs in chestnuts. © 2019 Society of Chemical Industry [ABSTRACT FROM AUTHOR]

The pesticide residue levels of three nuts (chestnut, walnut, pinenut) collected from seven main producing areas of China were investigated. Twenty-nine pesticides, including organophosphates (OPs), organochlorines (OCs), pyrethroids (PYs) and two fungicides (triadimefon and buprofezin) were analyzed by gas chromatography (GC). Four OPs (acephate, dimethoate, chlorpyrifos and parathion-methyl) were found in 11.4% samples, with the concentrations of 19.0 µg kg −1 to 74.0 µg kg −1 . Six OCs (DDT, HCH, endosulfan, quintozene, aldrin and dieldrin) were found in 18.2% samples, with the concentrations of 2.0 µg kg −1 to 65.7 µg kg −1 . Among OCs, p,p-DDE and α-HCH were the dominant isomer for DDT and HCH. Five PYs (fenpropathrin, fenvalerate, cypermethrin, bifenthrin and cyhalothrin) were found in 15.9% samples, with the concentrations of 2.5 µg kg −1 to 433.0 µg kg −1 . Fenpropathrin was the most frequently detected pesticide. In addition, triadimefon and buprofezin were detected only in two samples. For the tested nuts, 25.0% samples with multiple residues (containing more than two pesticides) were noted, even up to 9.1% samples with five pesticide residues. The residue of 15.9% samples was higher than the maximum residue limits (MRLs) of China. The short-term risks for the tested nuts were below 1.2%, and the highest long-term risk was 12.58%. The cumulative risk (cHI) for the tested pesticides were 8.43% (OPs), 0.42% (OCs), 12.82% (PYs) and 0.15% (fungicides), respectively. The total cHI was 21.82%. There was no significant health risk for consumers via nuts consumption. [ABSTRACT FROM AUTHOR]

Extreme and uncontrolled usage of pesticides produces a number of problems for vegetation and human health. In this study, the existence of organophosphates (OPs), organochlorines (OCs), pyrethroids (PYs) and fungicides (FUs) were investigated in persimmons/jujubes and their planted soils, which were collected from China. One OP (dimethoate), three OCs (DDT, quintozene and aldrin), six PYs (bifenthrin, fenpropathrin, cyhalothrin, cypermethrin, fenvalerate and deltamethrin) and two FUs (triadimefon and buprofezin) were found in 36.4% of persimmons and 70.8% of jujubes, with concentrations from 1.0 μg/kg to 2945.0 μg/kg. The most frequently detected pesticides in the two fruits were fenpropathrin in persimmons and cypermethrin in jujubes, with the detection frequencies of 30.0% and 22.7%, respectively. The residues of 4.5% (persimmon) and 25.0% (jujube) of samples were higher than the maximum residue limits (MRLs) of China. Compared with the fruits, more types of pesticides and higher residues were observed in their planted soils. The most frequently detected pesticides were HCH in persimmon soil and DDT in jujube soil, with the detection frequencies of 10.9% and 12.7%, respectively. For the tested samples, 39.1% of fruit samples and 63.0% of soil samples with multiple residues (containing more than two pesticides) were noted, even up to 8 residues in fruits and 14 residues in soils. Except for cyhalothrin, the other short-term risks for the tested pesticides in the fruits were below 10%, and the highest long-term risk was 14.13% for aldrin and dieldrin. There was no significant health risk for consumers via consumption of the two fruits. [ABSTRACT FROM AUTHOR]

Distribution behaviors of thifluzamide, fenoxanil, and tebuconazole applied to rice were investigated in South China. Analysis was by a modified QuEChERS method with gas chromatography (thifluzamide and fenoxanil) and liquid chromatography mass spectrometry (tebuconazole). Thifluzamide and tebuconazole partitioned mainly into the soil, with half-lives in the paddy soil of 12–14 and 5.3–7.8 days, respectively. Fenoxanil partitioned mainly into the rice plants, with half-lives of 3.3–4.4 days. The half-lives of thifluzamide, fenoxanil, and tebuconazole in paddy water were 0.17–0.89, 1.8–3.0, and 1.6–4.0 days, respectively. The residues in rice grains at the pre-harvest interval of 14 days were all below the established maximum limit values. The dietary risks assessed as hazard quotients at the pre-harvest interval were less than 1. [ABSTRACT FROM AUTHOR]

The effects of two formulations (emulsifiable concentrate (EC) and granule (G)) on the distribution, degradation, sorption, and residue risk of chlorpyrifos (CHP) were investigated in two producing areas of bamboo shoot. The results showed that CHP was mainly distributed in the topsoil (0-5 cm, P < 0.05), with the proportion of CHP in the total quantity ranging from 76.0 to 100.0 % (G) and 12.0 to 98.1 % (EC), respectively. The degradation of CHP-EC in soils (half-life 27.7-36.4 days) was faster than that of CHP-G in soils (half life above 120-150 days). The main metabolite of CHP, 3,5,6-trichloro-2-pyridinol (TCP), was found in soil samples. CHP showed good sorption ability in the two tested soils, with the sorption coefficient (K) of 43.76 and 94.43 mg/kg. The terminal residues of CHP in bamboo shoots were in the range of 15.2-75.6 (G) and 10.4-35.7 μg/kg (EC), respectively. The soil type had a notable effect on the CHP behaviors in soil ( P < 0.05, especially for CHP-G), but it did not affect the metabolite of CHP. Although some positive bamboo shoot samples (CHP residue exceeding maximum residue limits) were found, the hazard quotients did not exceed 7 %, which meant there was a negligible risk associated with the exposure to CHP via the consumption of bamboo shoots. [ABSTRACT FROM AUTHOR]

The potential health risk of trace elements in nut foods has been widely concerned. The accumulations of trace elements by plants in the environment are disturbed by multiple factors. The objective of this work was to investigate the risk levels of trace elements in walnuts and their influence factors (planting area and cultivar). A total of 228 walnut samples were collected from four major walnut producing areas of China. The contents of essential elements for Fe, Cu, Zn, Mo and Se were 35.8, 21.9, 14.8, 0.3 and 0.04 mg/kg, respectively. The contribution of Cu for dietary reference intake was as high as 82.22%. The risk levels of potential toxicological elements and toxic elements within the acceptable limits. Significantly, the hazard quotients (HQs) of Ba and Co were up to 26.14% and 25.31%, respectively. The effect of planting area on trace elements was determined from the aspects of regional distribution and urbanization. Significant differences of essential elements were found between northeast and northwest areas. The urbanization directly influenced toxic elements, which could cause variation up to 85.0% (Pb) and 42.9% (As). Finally, cultivar effect was confirmed that all walnut cultivars were divided into four categories with different trace element characteristics. Image 1 • The dietary risk levels of toxic elements (hazard quotient ≪ 1%) were negligible. • Significant differences of essential elements were found between northeast and northwest areas of China. • The urbanization has direct effect on toxic elements in walnuts, especially for Pb and As. • Four categories of walnut cultivars could be classified based on the analyzed trace elements. [ABSTRACT FROM AUTHOR]