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Dissipation behaviors and residues of carbendazim and diethofencarb in combination in tomato were investigated. The half-lives were 2.1–3.4 days for carbendazim, and 1.8–3.2 days for diethofencarb at a dose of 1.5 times of the recommended dosage. The residues of carbendazim and diethofencarb were below the maximum residue limits (MRLs) in China one day after application of the combination. The ultimate residues were significantly lower than the maximum permissible intake (MPI) in China at the recommended high dose for both child and adult. The values of the maximum dietary exposure for carbendazim and diethofencarb were 0.26 and 0.27 mg per person per day, respectively. The theoretical maximum daily intake (TMDI) values for carbendazim and diethofencarb were 1.5 and 0.5 mg/day, respectively. The dietary exposure was lower than the MPI, which indicates the harvested tomato samples under the experimental conditions (open field) are safe for human consumption at the recommended high dosage of the wettable powder. [ABSTRACT FROM AUTHOR]

Atrazine is one of the most frequently detected pesticides and poses a great risk to humans and the environment. In this study, the effects of two submerged macrophytes, Potamogeton crispus and Myriophyllum spicatum, on phytoremediation of atrazine were evaluated. The results showed that atrazine decayed faster in the pots where these two plants were cultivated than that of the control without the plants during the 60-day course of the experiment. Metabolite analyses of atrazine indicated that atrazine was mainly converted to diaminochlorotriazine and hydroxyatrazine. Dissipation kinetics and risk assessment of atrazine showed that atrazine was degraded rather fast in maize and generally safe for human consumption at the recommended high dosage of atrazine. The maximum permissible intake (MPI) for atrazine was calculated to be 0.23 μg/person/day for a child and 0.72 μg/person/day for an adult. However, due to the large-scale application of atrazine over the years, the atrazine residue still poses a great threat to the environment. By using submerged macrophytes M. spicatum and P. crispus, atrazine could be absorbed from the sediment, hence remediating contaminated sediment and water. This study established a protocol for evaluating submerged plants in absorption or phytoremediation of pesticides. [ABSTRACT FROM AUTHOR]

Polycyclic aromatic hydrocarbons (PAHs) are a group of organic environmental pollutants posing a potential risk to human health. This study was constructed to investigate the presence of 16 PAHs in six commonly consumed vegetables collected from the markets in Shandong, China by a quick, easy, cheap, effective, rugged, safe (QuEChERS)-based extraction method coupled with gas chromatography-mass spectrometry (GC-MS). Our results showed that the vegetables were polluted with PAHs at an alarming level, of which celery contained the highest total concentration of PAHs (Σ16 PAH), whereas cucumbers contained the lowest Σ16 PAH. Besides, the dietary exposure of PAHs was assessed in these vegetables based on the maximum Σ16 PAH. The results showed that the populations in Shandong were exposed to 23-213 ng/d of PAHs through these six vegetables, suggesting that vegetables are the major sources of PAHs in the diet. Hence, it is necessary to monitor the PAH levels in vegetables. Our study provides guidance for future legislative actions regarding PAH levels in vegetables in China. [ABSTRACT FROM AUTHOR]

Objective Residue risk assessment of pesticides in celery was conducted to provide a scientific basis for agricultural regulation policies and working procedures. Methods Three hundred samples from eight main growing regions in China were collected and pesticide residue analyses were performed using GC–MS/MS and LC-MS/MS methods. Both chronic and acute intake risk of pesticides were assessed. Furthermore, intake risk of each detected pesticide was ranked according to a predefined ranking matrix. Results (1) Out of these 300 samples, 175 were revealed to contain one or more pesticide residues. Twenty-five pesticides were identified in total, out of which, carbofuran was found to exceed the maximum residue limit. (2) Chronic and acute intake risks were evaluated and lie in between 0 and 1.80 and between 0.05 and 28.0 for these twenty-five pesticides, respectively. (3) Intake risk of individual pesticide was ranked; five pesticides, including avermectin, triazophos, chlorpyrifos, dimethoate oxygen, and carbofuran posed the highest risks. Conclusion Pesticide residues were detected in more than 58% celery samples in our study. Most pesticides have a residue level lower than their maximum residue limit and pose low chronic and acute dietary intake risk. However, usage of some pesticides like carbofuran should be closely monitored and regulated in the future. [ABSTRACT FROM AUTHOR]