Eleven recently completed toxicological studies were critically reviewed to identify toxicologically significant endpoints and dose-response information. Dose-response data were compiled and entered into the USEPA＇s ...Eleven recently completed toxicological studies were critically reviewed to identify toxicologically significant endpoints and dose-response information. Dose-response data were compiled and entered into the USEPA＇s benchmark dose software （BMDS） for calculation of a benchmark dose （BMD） and a benchmark dose low （BMDL）. After assessing 91 endpoints across the nine studies, a total of 23 of these endpoints were identified for BMD modeling, and BMDL estimates corresponding to various dose-response models were compiled for these separate endpoints. Thyroid, neurobehavior and reproductive endpoints for BDE-47, -99, -209 were quantitatively evaluated. According to methods and feature of each study, different uncertainty factor （UF） value was decided and subsequently reference doses （RfDs） were proposed. Consistent with USEPA, the lowest BMDLs of 2.10, 81.77, and 1698 I^g/kg were used to develop RfDs for BDE-47, -99, and -209, respectively. RfDs for BDE-99 and BDE-209 were comparable to EPA results, and however, RfD of BDE-47 was much lower than that of EPA, which may result from that reproductive/developmental proves to be more sensitive than neurobehavior for BDE-47 and the principal study uses very-low-dose exposure.展开更多
Allowable levels for pesticide residues in foods, known as tolerances in the US and as maximum residue limits （MRLs） in much of the world, are widely yet inappropriately perceived as levels of safety concern. A nove...Allowable levels for pesticide residues in foods, known as tolerances in the US and as maximum residue limits （MRLs） in much of the world, are widely yet inappropriately perceived as levels of safety concern. A novel approach to develop scientifically defensible levels of safety concern is presented and an example to determine acute and chronic pesticide food safety standard （PFSS） levels for the fungicide captan on strawberries is provided. Using this approach, the chronic PFSS level for captan on strawberries was determined to be 2 000 mg kg-1 and the acute PFSS level was determined to be 250 mg kg-1. Both levels are far above the existing tolerance and MRLs that commonly range from 3 to 20 mg kg-~, and provide evidence that captan residues detected at levels greater than the tolerance or MRLs are not of acute or chronic health concern even though they represent violative residues. The benefits of developing the PFSS approach to serve as a companion to existing tolerances/MRLs include a greater understanding concerning the health significance, if any, from exposure to violative pesticide residues. In addition, the PFSS approach can be universally applied to all potential pesticide residues on all food commodities, can be modified by specific jurisdictions to take into account differences in food consumption practices, and can help prioritize food residue monitoring by identifying the pesticide/commodity combinations of the greatest potential food safety concern and guiding development of field level analytical methods to detect pesticide residues on prioritized pesticide/commodity combinations.展开更多
Data on the presence of organophosphate esters(OPEs)in drinking water and its significance as a pathway of exposure are limited.In this study,we measure for the first time,concentrations of eight OPEs in 50 UK drinkin...Data on the presence of organophosphate esters(OPEs)in drinking water and its significance as a pathway of exposure are limited.In this study,we measure for the first time,concentrations of eight OPEs in 50 UK drinking water samples.Arithmetic mean concentrations of ∑8OPEs were:6.4 and 11 ng/L in bottled(n=25)and tap water samples(n=25),respectively.Concentrations of ∑8OPEs in tap water(mean:11 ng/L)exceed significantly those in bottled water(mean:6.4 ng/L)(p˂0.01).Moreover,UK tap water is more contaminated with chlorinated,aryl-,and alkyl-OPEs than bottled water.The predominant OPEs detected were:tris(butoxyethyl)phosphate(TBOEP),tris(2-chloroethyl)phosphate(TCEP),and tris(2-chloroisopropyl)phosphate(TCIPP)with arithmetic mean concentrations in the two water sample types ranging between(3.5e3.8 ng/L),(0.60-3.0 ng/L),and(1.02-2.9 ng/L),respectively.Estimated daily intakes(EDIs)(mean and high-end exposure)via drinking water for different sectors of the UK population were:infants(0.93 and 6.4 ng/kg bw/day)˃toddlers(0.46 and 3.1 ng/kg bw/day)˃children(0.35 and 2.3 ng/kg bw/day)˃adults(0.28 and 2.1 ng/kg bw/day).Based on these data,exposure to ∑8OPEs via drinking water is much lower than via:food,indoor dust ingestion,inhalation,and dermal uptake for adults and toddlers.Reassuringly,our EDIs were lower than relevant reference dose(RfD)values.However,combining our drinking water ingestion data with exposure via other pathways revealed overall exposure to 2-ethylhexyl diphenyl phosphate(EHDPP)and TCIPP to approach health-based limit values for UK toddlers under a high-end exposure scenario.展开更多
基金financially supported by the Natural Science Foundation of China(Grant 81072263,to Y.Z.)Chun Tsung Scholarship of Fudan University(to D.C.)
文摘Eleven recently completed toxicological studies were critically reviewed to identify toxicologically significant endpoints and dose-response information. Dose-response data were compiled and entered into the USEPA＇s benchmark dose software （BMDS） for calculation of a benchmark dose （BMD） and a benchmark dose low （BMDL）. After assessing 91 endpoints across the nine studies, a total of 23 of these endpoints were identified for BMD modeling, and BMDL estimates corresponding to various dose-response models were compiled for these separate endpoints. Thyroid, neurobehavior and reproductive endpoints for BDE-47, -99, -209 were quantitatively evaluated. According to methods and feature of each study, different uncertainty factor （UF） value was decided and subsequently reference doses （RfDs） were proposed. Consistent with USEPA, the lowest BMDLs of 2.10, 81.77, and 1698 I^g/kg were used to develop RfDs for BDE-47, -99, and -209, respectively. RfDs for BDE-99 and BDE-209 were comparable to EPA results, and however, RfD of BDE-47 was much lower than that of EPA, which may result from that reproductive/developmental proves to be more sensitive than neurobehavior for BDE-47 and the principal study uses very-low-dose exposure.
基金the Chilean Government and the National Commission for Scientific and Technological Research (CONICYT) for supporting this work through the Becas Chile Scholarships
文摘Allowable levels for pesticide residues in foods, known as tolerances in the US and as maximum residue limits （MRLs） in much of the world, are widely yet inappropriately perceived as levels of safety concern. A novel approach to develop scientifically defensible levels of safety concern is presented and an example to determine acute and chronic pesticide food safety standard （PFSS） levels for the fungicide captan on strawberries is provided. Using this approach, the chronic PFSS level for captan on strawberries was determined to be 2 000 mg kg-1 and the acute PFSS level was determined to be 250 mg kg-1. Both levels are far above the existing tolerance and MRLs that commonly range from 3 to 20 mg kg-~, and provide evidence that captan residues detected at levels greater than the tolerance or MRLs are not of acute or chronic health concern even though they represent violative residues. The benefits of developing the PFSS approach to serve as a companion to existing tolerances/MRLs include a greater understanding concerning the health significance, if any, from exposure to violative pesticide residues. In addition, the PFSS approach can be universally applied to all potential pesticide residues on all food commodities, can be modified by specific jurisdictions to take into account differences in food consumption practices, and can help prioritize food residue monitoring by identifying the pesticide/commodity combinations of the greatest potential food safety concern and guiding development of field level analytical methods to detect pesticide residues on prioritized pesticide/commodity combinations.
文摘Data on the presence of organophosphate esters(OPEs)in drinking water and its significance as a pathway of exposure are limited.In this study,we measure for the first time,concentrations of eight OPEs in 50 UK drinking water samples.Arithmetic mean concentrations of ∑8OPEs were:6.4 and 11 ng/L in bottled(n=25)and tap water samples(n=25),respectively.Concentrations of ∑8OPEs in tap water(mean:11 ng/L)exceed significantly those in bottled water(mean:6.4 ng/L)(p˂0.01).Moreover,UK tap water is more contaminated with chlorinated,aryl-,and alkyl-OPEs than bottled water.The predominant OPEs detected were:tris(butoxyethyl)phosphate(TBOEP),tris(2-chloroethyl)phosphate(TCEP),and tris(2-chloroisopropyl)phosphate(TCIPP)with arithmetic mean concentrations in the two water sample types ranging between(3.5e3.8 ng/L),(0.60-3.0 ng/L),and(1.02-2.9 ng/L),respectively.Estimated daily intakes(EDIs)(mean and high-end exposure)via drinking water for different sectors of the UK population were:infants(0.93 and 6.4 ng/kg bw/day)˃toddlers(0.46 and 3.1 ng/kg bw/day)˃children(0.35 and 2.3 ng/kg bw/day)˃adults(0.28 and 2.1 ng/kg bw/day).Based on these data,exposure to ∑8OPEs via drinking water is much lower than via:food,indoor dust ingestion,inhalation,and dermal uptake for adults and toddlers.Reassuringly,our EDIs were lower than relevant reference dose(RfD)values.However,combining our drinking water ingestion data with exposure via other pathways revealed overall exposure to 2-ethylhexyl diphenyl phosphate(EHDPP)and TCIPP to approach health-based limit values for UK toddlers under a high-end exposure scenario.
