scholarly journals Risk assessment of an organochlorine pesticide mixture in the surface waters of Qingshitan Reservoir in Southwest China

RSC Advances ◽  
2018 ◽  
Vol 8 (32) ◽  
pp. 17797-17805 ◽  
Author(s):  
Honghu Zeng ◽  
Xin Fu ◽  
Yanpeng Liang ◽  
Litang Qin ◽  
Lingyun Mo
Keyword(s):  
Risk Assessment ◽  
Organochlorine Pesticide ◽  
Surface Waters ◽  
Southwest China ◽  
Pesticide Mixture

Risk assessment of single pollutants has been extensively studied.

scholarly journals Reforestation Impacted Soil Heavy Metal Fractionation and Related Risk Assessment in the Karst Area, Southwest China

Forests ◽  
2021 ◽  
Vol 12 (7) ◽  
pp. 891
Author(s):  
Qian Zhang ◽  
Guilin Han ◽  
Xingliang Xu
Keyword(s):  
Heavy Metals ◽  
Risk Assessment ◽  
Ecological Risk ◽  
Southwest China ◽  
Risk Index ◽  
Contamination Factor ◽  
Karst Area ◽  
Risk Assessment Code ◽  
Bcr Sequential Extraction ◽  
Soil Heavy Metals

Human agricultural activities have resulted in widespread land degradation and soil contamination in the karst areas. However, the effects of reforestation after agricultural abandonment on the mobility risks and contamination of heavy metals have been rarely reported. In the present study, six soil profiles were selected from cropland and abandoned cropland with reforestation in the Puding karst regions of Southwest China. The Community Bureau of Reference (BCR) sequential extraction method was used to evaluate the compositions of different chemical fractions of soil heavy metals, including Fe, Mn, Cr, Zn, Ni, and Cd. The total contents of Cr, Ni, Zn, Cd, and Mn in the croplands were significantly higher than those in the abandoned croplands. For all soils, Cr, Ni, Zn, and Fe were mainly concentrated in the residual fractions (>85%), whereas Mn and Cd were mostly observed in the non-residual fractions (>65%). The non-residual fractions of Cd, Cr, Ni, and Zn in the croplands were higher than those in the abandoned croplands. These results indicated that the content and mobility of soil heavy metals decreased after reforestation. The individual contamination factor (ICF) and risk assessment code (RAC) showed that Cd contributed to considerable contamination of karst soils. The global contamination factor (GCF) and potential ecological risk index (RI) suggested low contamination and ecological risk of the investigated heavy metals in the croplands, moreover they can be further reduced after reforestation.

scholarly journals Total and bioaccessible heavy metals in cabbage from major producing cities in Southwest China: health risk assessment and cytotoxicity

RSC Advances ◽  
2021 ◽  
Vol 11 (20) ◽  
pp. 12306-12314
Author(s):  
Mengying Li ◽  
Yishu Qin ◽  
Chengchen Wang ◽  
Kun Wang ◽  
Zhihua Deng ◽  
...  
Keyword(s):  
Heavy Metals ◽  
Risk Assessment ◽  
Health Risk ◽  
Brassica Oleracea ◽  
Health Risk Assessment ◽  
Southwest China

We analyzed the total and bioaccessible concentrations of heavy metals in a popular vegetable cabbage (Brassica oleracea) from producing cities in Yunnan, Southwest China and assessed their health risk based on both bioaccessibility and cytotoxicity.

scholarly journals Risk Assessment of Malakite with the Active Substances Dithianon and Pyrimenthanil

2019 ◽  
pp. 312-314
Author(s):  
Torsten Källqvist ◽  
Merete Grung ◽  
Katrine Borgå ◽  
Hubert Dirven ◽  
Ole Martin Eklo ◽  
...  
Keyword(s):  
Risk Assessment ◽  
Surface Waters ◽  
Plant Protection ◽  
Aquatic Organisms ◽  
Toxicity Tests ◽  
Concentration Addition ◽  
Active Ingredients ◽  
Active Substances ◽  
Assessment Factor

The plant protection product Malakite (BAS 669 01 F), containing the active substances dithianon and pyrimethanil, is a fungicide against scab in pome fruits. Products containing these active plant protection substances are approved in Norway, but not with both substances in the same product. The Swedish Chemicals Agency (KemI) has as zonal Rapporteur Member State (zRMS) of the Northern Zone evaluated the product Malakite and decided on non-approval due to the observation of unacceptable effects in exposed birds, aquatic organisms, non-target arthropods and earthworms. On request from The Norwegian Food Safety Authority, the VKM Panel on Plant Protection Products has discussed the available data and the report prepared by KemI, and has concluded as follows on the questions raised: On the refinement of DT50 in long term risk assessment for birds: It is the view of the VKM panel that the refinement is not acceptable because the analysis using first order kinetics seems not in line with a realistic and sufficiently conservative approach for the data provided. Furthermore, field studies from more sites are required. On the long term cumulative effects of the active substances on birds: VKM shares the view of KemI, that the combined sub-lethal and reproduction effects should be assessed because the mode of action of the two ingredients has only been shown in fungi, and since the mechanisms in birds could be different. On the reduction of assessment factor for fish: VKM opposes to the reduction of assessment factor for dithianon in fish because the data from acute toxicity tests cannot be extrapolated to chronic toxicity, and because the factor should reflect not only the variation in interspecies sensitivity, but also the uncertainty involved in extrapolation from laboratory tests to the field situation. On the choice of end point in risk assessment for fish: The VKM panel considers the NOEC of dithianon for fish determined from the study at pH 7.9 not to be adequate for the more acidic Norwegian surface waters, and recommends using the data from the test performed at pH 6.5. On the formulation studies for aquatic organisms: It is the opinion of the VKM panel that the formulation studies may be used together with corresponding studies with the active ingredients as long as the studies compared are performed and evaluated according to the same principles. However, VKM notes that the formulation tests as well as the tests of the active ingredients have been performed at high pH values, which are not representative to most Norwegian surface waters. Thus, the toxic effect of dithianon shown in these tests are likely to be lower than expected under typical conditions in Norway. On the assessment factors for concentration addition in fish: It is the opinion of the VKM panel that a reduction in assessment factor for one component in a mixture cannot be used for a formulation containing components for which a similar reduction has not been accepted. On effect studies of active substances and formulations on non-target arthropods: The VKM panel shares the view of KemI that the risk assessment should be based on all available information, including the studies presented for the active substances. On the endpoint in earthworm risk assessment: VKM supports the view of KemI that the observed effects of pyrimethanil on reproduction of earthworms should be considered in the risk assessment of Malakite.

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