Data quality assessment for studies investigating microplastics and nanoplastics in food products: Are current data reliable?

● Data quality assessment criteria for MP/NPs in food products were developed. ● Data quality of 71 data records (69 of them only focused on MPs) was assessed. ● About 96% of the data records were considered unreliable in at least one criterion. ● Improvements need to be made regarding positive controls and polymer identification. ● A mismatch between MP/NPs used in toxicity studies and those in foods was recorded. Data on the occurrence of microplastics and nanoplastics (MP/NPs) in foods have been used to assess the human health risk caused by the consumption of MP/NPs. The reliability of the data, however, remains unclear because of the lack of international standards for the analysis of MP/NPs in foods. Therefore, the data quality needs to be assessed for accurate health risk assessment. This study developed 10 criteria applicable to the quality assessment of data on MP/NPs in foods. Accordingly, the reliability of 71 data records (69 of them only focused on MPs) was assessed by assigning a score of 2 (reliable without restrictions), 1 (reliable but with restrictions), or 0 (unreliable) on each criterion. The results showed that only three data records scored 2 or 1 on all criteria, and six data records scored 0 on as many as six criteria. A total of 58 data records did not include information on positive controls, and 12 data records did not conduct the polymer identification, which could result in the overestimation or underestimation of MP/NPs. Our results also indicated that the data quality of unprocessed foods was more reliable than that of processed foods. Furthermore, we proposed a quality assurance and quality control protocol to investigate MP/NPs in foods. Notably, the characteristics of MP/NPs used in toxicological studies and those existing in foods showed a remarkable discrepancy, causing the uncertainty of health risk assessment. Therefore, both the estimated exposure of MP/NPs and the claimed potential health risks should be treated with caution.     

Integrated risk assessment framework for transformation products of emerging contaminants: what we know and what we should know

● A better risk assessment can combine the improved non-target analysis method. ● Multi-evidence is advised in molecular determination and risk-based prioritization. ● Combining omics, multi-endpoint EDA, and machine learning to assess product risks. The continuous input of various emerging contaminants (ECs) has inevitably introduced large amounts of transformation products (TPs) in natural and engineering water scenarios. Structurally similar to the precursor species, the TPs are expected to possess comparative, if not more serious, environmental properties and risks. This review summarizes the state-of-the-art knowledge regarding the integrated risk assessment frameworks of TPs of ECs, mainly involving the exposure- and effect-driven analysis. The inadequate information within existing frameworks that was essential and critical for developing a better risk assessment framework was discussed. The main strategic improvements include (1) non-targeted product analysis in both laboratory and field samples, (2) omics-based high-throughput toxicity assessment, (3) multichannel-driven mode of action in conjugation with effect-directed analysis, and (4) machine learning technology. Overall, this review provides a concise but comprehensive insight into the optimized strategy for evaluating the environmental risks and screening the key toxic products from the cocktail mixtures of ECs and their TPs in the global water cycle. This facilitates deciphering the mode of toxicity in complex chemical mixtures and prioritizing the regulated TPs among the unknown products, which have the potential to be considered a class of novel “ECs” of great concern.     

长三角一体化示范区青浦区水环境中22种PPCPs的多介质分布特征及风险评估

采集了长三角一体化示范区青浦区(包括太浦河、金泽水库周边和青西郊野公园)的25个采样点的50个表层水体和沉积物样品,利用高效液相色谱串联质谱(HPLC/MS-MS)分析了样品中的22种药物与个人护理品(PPCPs),详细分析了研究区域目标PPCPs的分布特征、来源和影响因素,并利用商值法对目标PPCPs的生态风险和健康...     

生态产品市场化实现路径及二元价格体系

本文从微观经济学角度阐释生态产品的市场化实现路径及其价格机制。认为生态产品市场化路径的前提是存在有形的,能够体现劳动价值,可交换的产品实体。鉴于现有研究所讨论的生态产品价值的体现皆源于各环境要素的支撑,因此可将清洁的水、空气、土壤等优质环境要素凝练为生态产品的基本有形载体。在此基础上,本文指出政府提供生态产品的有效路径有三条:创造、维系改善及修复。其中修复路径是现阶段市场化的优先选择方式。通过结合现阶段我国新的环保商业化模式——合同环境服务这一新命题,本文构建了生态产品合同环境服务政府采购的有效市场化路径,即政府通过绩效合同采购第三方环保服务,以综合环境目标为合同标的,通过所采购的一体化环境修复项目实现提供良好的生态产品。在此基础上围绕生态产品价格组成,本文提出生态产品的二元价格体系:指出生态产品买入与卖出的不同经济行为对应着生态环境的保护与开发两种对立的发展模式,这两种市场行为的外部性存在正负两种情景。综合考虑生产资料所有者属性,本文创新性地提出生态产品市场交易应采用买入-卖出二元价格体系。买入价格也称保护价格,主要考虑生产成本与利润,生产成本即生态修复项目的费用支出,其中利润是购买者(政府)予以产品生产者(提供修复服务的环保服务商)适当的利润空间,作为该生产者经济行为正外部性的补贴;出让价格也称牺牲价格,包括生产成本、社会成本(外部性成本)、生产资料成本、利润等,其中出让行为价格组成中的社会成本获益是政府,应主要用于支付环境管理成本。值得注意的是,在二元价格体系中,学者们讨论的生态产品价值与买入价格相关性不大,在数值或更接近出让价格。     

蔬菜出口产地农户对食品安全规制的认知及其农药决策行为研究

食品安全与农药残留一直是备受关注的焦点问题。基于此,本文应用山东省蔬菜出口产地安丘市392个农户的调查数据,对农户食品安全规制的认知及其农药使用行为的影响因素进行了分析。研究结果表明,农户的学历层次、农产品国内销售和出口日本的比例、农户对国内外农产品市场的评价及是否接受农药残留检测显著影响其对食品安全规制的认知;而农户的平均生产支出、是否接受农药残留检测、检测标准的严格程度及是否作生产记录影响其农药使用行为。此外,本文发现该制度的实施导致一些农户产生逆向选择,且农户的农药使用因种植结构而不同。针对当前农业生产的特点和食品安全现状,为了促进当地农业生产方式的转变和保护生态环境,政府应加强对农业主体的培训和技术指导,引导当地农户加强与产业组织的联系,有效开展农药残留检测、优化种植结构,提高农产品的质量和国际竞争力。     

Expression and functional analysis of three nicosulfuron-degrading enzymes from Bacillus subtilis YB1

To investigate the degradation activity of the manganese ABC transporter, vegetative catalase 1 and acetoin dehydrogenase E1 from Bacillus subtilis YB1, the proteins were prokaryotically expressed and purified. Assay results showed that the three enzymes were able to degrade nicosulfuron (2- (4,6-dimethoxypyrimidine-2-pyrimidinylcarbamoylaminosulfonyl) -N,N-dimethylnicotinamide), with vegetative catalase 1 exhibiting the highest activity. To further examine the degradation pathway, the degradation products of the three enzymes and the YB1 strain were detected by liquid chromatography-mass spectrometry(LC-MS). The nicosulfuron degradation products of the three enzymes were consistent with those of the YB1 strain, indicating the presence of two pathways: one due to cleavage of sulfonylurea bridges and ring-opening of 1-(4,6-dimethoxy-pyrimidin-2-yl)-3-(2-methyliminomethanesulfonyl-acetyl)-ureaas the pyrimidine ring, yielding the product; and the another due to cleavage of a sulfonylurea bridge, yielding 4,6-dihydroxy pyrimidine (111 m/z), 2-ylamine ?4,6-dimethoxy pyrimidine and ((4-(dimethycarbamoyl)pyridine-2-yl)sulfonyl)carbamic acid as products, which were further degraded to 4,6-dihydroxy pyrimidine and N,N-dimethyl-2-sulfamoyl-isonicotinamide. The above results reveal a major contribution of extracellular enzymes to the degradation of nicosulfuron by the YB1 strain. Our data help in elucidation of the mechanism of nicosulfuron bio-degradation and may facilitate the construction of engineered strains.     

氢化物发生-原子荧光法测定生活垃圾堆肥产品中砷

通过试验研究,建立了硝酸-高氯酸消解,原子荧光法测定生活垃圾堆肥产品中的砷.该方法的检出限为0.06mg/kg(按称取0.5g试样消解定客至50ml计算),用于不同地域堆肥样品中砷的测定,其相对标准偏差(RSD)均在8.99%以下.加标回收率介于89.0%～107.0%之间.     

环境中多溴联苯醚(PBDEs)的代谢转化研究现状

多溴联苯醚(PBDEs)作为一种溴系阻燃剂(BFRs),在多种环境介质和生物体内广泛存在且浓度逐年增加,因而越来越多地受到研究者关注.综合PBDEs各方面研究报道,认为其在环境中存在生物和非生物两种转化方式.非生物转化主要是光降解,即PBDEs在光照条件下可通过自由基反应脱溴生成低溴同系物及多溴联苯呋喃(PBDFs).生物转化则包括微生物转化、生物体内转化和生物体外代谢,其转化代谢途径除脱溴外,还有醚键断裂、羟基化和羟基化/脱溴等.对PBDEs在环境中不同转化方式的转化速率、转化途径和转化产物等的研究现状进行综述,对今后PBDEs在环境中归趋、生态风险和健康评价研究将起到一定的指导作用.     

电磁干扰环境下产品失效机理分析

论述了电磁干扰环境对产品所产生的影响,阐述了在此环境下产品的失效模式,分析了在电磁干扰环境应力下产品功能失效的原因,指出了产品一般都会受到电磁波感应耦合、核电磁脉冲、静电失效、雷电电磁脉冲等干扰的影响作用,并针对性地提出了对产品进行有效防护的方法。     

Prioritizing research for trace pollutants and emerging contaminants in the freshwater environment

Organic chemicals have been detected at trace concentrations in the freshwater environment for decades. Though the term trace pollutant indicates low concentrations normally in the nanogram or microgram per liter range, many of these pollutants can exceed an acceptable daily intake (ADI) for humans. Trace pollutants referred to as emerging contaminants (ECs) have recently been detected in the freshwater environment and may have adverse human health effects. Analytical techniques continue to improve; therefore, the number and frequency of detections of ECs are increasing. It is difficult for regulators to restrict use of pollutants that are a human health hazard; scientists to improve treatment techniques for higher priority pollutants; and the public to modify consumption patterns due to the vast number of ECs and the breadth of literature on the occurrence, use, and toxicity. Hence, this paper examines literature containing occurrence and toxicity data for three broad classes of trace pollutants and ECs (industrials, pesticides, and pharmaceuticals and personal care products (PPCPs)), and assesses the relevance of 71 individual compounds. The evaluation indicates that widely used industrials (BPF) and PPCPs (AHTN, HHCB, ibuprofen, and estriol) occur frequently in samples from the freshwater environment but toxicity data were not available; thus, it is important to establish their ADI. Other widely used industrials (BDE-47, BDE-99) and pesticides (benomyl, carbendazim, aldrin, endrin, ethion, malathion, biphenthrin, and cypermethrin) have established ADI values but occurrence in the freshwater environment was not well documented. The highest priority pollutants for regulation and treatment should include industrials (PFOA, PFOS and DEHP), pesticides (diazinon, methoxychlor, and dieldrin), and PPCPs (EE2, carbamazepine, βE2, DEET, triclosan, acetaminophen, and E1) because they occur frequently in the freshwater environment and pose a human health hazard at environmental concentrations.