Currently used organophosphate and brominated flame retardants in the environment of China and other developing countries (2000–2016)

This review summarizes the environmental occurrence of new brominated flame retardants (NBFRs) and organophosphate compounds (OPs) in the environment of developing countries since 2000. The ban on the production and use of commercial formulations of polybrominated diphenyl ethers (PBDEs) have paved the way for the high use of NBFRs and OPs in consumer products to fulfill the fire safety regulations. Recent studies have shown that the ever increasing production volumes and extensive use of these chemicals as additive FRs and plasticizers have resulted into their ubiquitous occurrence in all environmental compartments. Although presumed to be safe for use and the environment, recent studies on their occurrence and persistence in the environment have raised questions. Due to the lack of awareness, research interest, and availability of technical facilities, limited scientific data is available on the occurrence of these chemicals in developing countries. In this study, we collected reported data and provide an overview of environmental occurrence of NBFRs and OPs in abiotic and biotic matrices of different developing countries. Finally, research gaps were identified with recommendations for future research work and would be useful towards the environmental management of these toxic chemicals.     

Ozonation of metoprolol in aqueous solution: ozonation by-products and mechanisms of degradation

This study investigated the degradation pathway of metoprolol, a widely used β-blocker, in the ozonation via the identification of generated ozonation by-products (OPs). Structure elucidation of OPs was performed using HPLC coupled with quadrupole time-of-flight high-resolution mass spectrometry. Seven OPs were identified, and four of these have not been reported elsewhere. Identified OPs of metoprolol included aromatic ring breakdown by-products; aliphatic chain degraded by-products and aromatic ring mono-, di-, and tetrahydroxylated derivatives. Based on the detected OPs, metoprolol could be degraded through aromatic ring opening reaction via reaction with ozone (O₃) and degradation of aliphatic chain and aromatic ring via reaction with hydroxyl radical (?OH).     

水中痕量有机磷农药的高效液相色谱/质谱分析

农药对饮用水以及饮用水源的污染在西方发达国家是一项极为关注的课题。有机磷农药作为农药中的一大类,至今仍是世界上生产和使用最多的农药品种。因此,饮用水以及饮用水源中痕量有机磷农药残留的状况受到人们关注。水中痕量有机磷农药的分析方法正在不断地改进,针对ＧＣ／ＭＳ测定某些有机磷农药时存在热分解以及在气相色谱柱上发生吸附的不足。结合高灵敏度、高选择性的质谱鉴定器,本文主要介绍最新的ＨＰＬＣ／ＡＰＩＭＳ方法在水中痕量有机磷农药测定方面的进展和应用。     

Quantitative structure-toxicity relationships of organophosphorous pesticides to fish (Cyprinus carpio)

This study was conducted to determine the relationships between 1381 chemical and structural parameters of 43 organophosphorus pesticides (OPs) and their toxicity to fish, Cyprinus carpio, using ChemOffice 8.03 and Dragon 2.1. By multivariate linear regression and intervariable regression analyses, various equations have been derived to calculate the lethal toxicity value, LC(50), for 43 OPs found in fish with different levels of toxicity. Results show that for all selected OPs, especially those of low toxic OPs (LC(50)< 2.5 mM), the equation, LC(50) = 56.259 - 13.071 lg K(ow)+17.510 MATS8P-17.455 Mor24u - 0.085 MW + 1.706 (lg K(ow))(2) + 2.306 (Mor14e)(2) + 6.849 Mor20 m (n = 43, F = 36.815, r = 0.942, r(adj)(2) = 0.862, SE = 2.899, p < 10(-6)), could account for 86.2% of the variability of the toxic effect. The steric and electronic characteristics and the hydrophobicity of OPs, in particular, are among the most important parameters determining the toxicity of OPs to fish. For the OPs with high toxicity, different structural parameters were introduced into the following two equations: LC(50)=3.795-1.195 (H1p)(2)-0.037 U-2.225 MATS3v-19.593 Tcon (n = 16, F = 56.820, r = 0.977, r(adj)(2) = 0.937, SE = 0.143, p < 10(-6)), where LC(50) is less than 2.5 mM, and LC(50) = 0.341-0.561 (HOMA)(2) + 0.231 HOMA (n = 3,r(adj)(2) = 1), where LC(50) is less than 0.3 mM. These results suggest that chemical and structural parameters could be useful in modeling chemical reactivity within homologous series of OP compounds and elucidating possible mechanisms associated with different levels of toxicity to fish.     

Quantitative structure-toxicity relationship study of lethal concentration to tadpole (Bufo vulgaris formosus) for organophosphorous pesticides

In the present study more than 1,000 structural parameters of 41 organophosphorus pesticides (OPs) were calculated using the software ChemOffice 8.03 and Dragon 2.1. Then, with multivariate linear regression and best subset regression analyses, different equations were derived to calculate the lethal toxicity, LC(50), for these 41 organophosphorous pesticides found in tadpoles (Bufo vulgaris formosus). An equation was developed for all selected OPs, especially those with relatively low toxicity levels (LC(50)>4.5mM) that accounted for 89.09% of the variability in the toxic effect. The equation indicated that the main contributions to OPs toxicity with tadpoles were the electrostatic contribution qH(+) (maximum net positive H atomic charge), spatial autocorrelation (MATS7 m) and hydrophobicity (lgK(ow)), with the two former being the most important parameters. For OPs with high toxicity, however, different structural parameters were introduced. The following equation was developed with LC(50)<4.5mM. These equations implied that with different levels of toxicity there could have different mechanisms in the tadpole. Furthermore, the results showed that molecular structural parameters had a particular value in modeling chemical reactivity within a homologous series of compounds.     

Organopesticides and fertility: where does the link lead to?

Environmental Science and Pollution Research - Organopesticides (OPs) are a group of various synthetic chemicals prevalently used in agriculture and homestead plantations. OPs were originally...     

利用基因工程菌BL21处理有机磷混合农药废水的研究

研究了悬浮状态和固定化状态的基因工程菌BL21对有机磷混合农药废水的降解特性.工程菌能快速、高效地降解有机磷混合农药,其最适底物是对硫磷,而马拉硫磷不能被工程菌降解.不同农药降解速率的差别造成了不同有机磷农药的降解过程需要用不同的动力学模型来描述.比较固定化状态和悬浮状态的工程菌的降解效果可知,固定化工程菌的降解活性较后者明显降低,其比降解速率大约仅为后者的20%.考察固定化工程菌长期运行的效果,发现其降解活性保存良好,工程菌稳定性大大提高,未出现固定化细胞溶涨、破碎现象.固定化后,工程菌的比降解速率虽然比悬浮工程菌降低了,但固定化工程菌更适用于长期运行的废水处理系统.     

Organophosphorus flame retardants and plasticizers in the atmosphere of the North Sea

Air samples collected in the German part of the North Sea from March to July 2010 were investigated for organophosphorus compounds (OPs) being applied as flame retardants and plasticizers. The ∑₈OPs concentration ranged from 110 to 1400 pg m⁻³ while tris(2-chloroisopropyl) phosphate (TCPP) dominated all samples with individual concentrations up to 1200 pg m⁻³. The highest concentrations were observed in continental air masses showing the high influence of industrialized regions including production sites on atmospheric emissions and concentrations. The occurrence of OPs even in oceanic/Arctic air masses shows that OPs can undergo long-range atmospheric transport. Dry particle-bound deposition fluxes from 9 to 240 ng m⁻² d⁻¹ for ∑₈OPs were estimated leading to a minimum annual flux of 710 ± 580 kg y⁻¹ OPs into the German North Sea. This study presents the first occurrence of OPs in the marine atmosphere together with important information on their long-range transport potential.     

Pesticide exposure and serum organochlorine residuals among testicular cancer patients and healthy controls

The incidence of testicular cancer (TC) has been increasing worldwide during the last decades. The reasons of the increase remains unknown, but recent findings suggest that organochlorine pesticides (OPs) could influence the development of TC. A hospital-based case-control study of 50 cases and 48 controls was conducted to determine whether environmental exposure to OPs is associated with the risk of TC, and by measuring serum concentrations of OPs, including p,p'-dichlorodiphenyldichloroethylene (p,p'-DDE) isomer and hexachlorobenzene (HCB) in participants. A significant association was observed between TC and household insecticide use (odds ratio [OR] = 3.01, 95 % CI: 1.11-8.14; OR(adjusted) = 3.23, 95 % CI: 1.15-9.11). Crude and adjusted ORs for TC were also significantly associated with higher serum concentrations of total OPs (OR = 3.15, 95 % CI: 1.00-9.91; OR(adjusted) = 3.34, 95 % CI: 1.09-10.17) in cases compared with controls. These findings give additional support to the results of previous research that suggest that some environmental exposures to OPs may be implicated in the pathogenesis of TC.     

Effects of organophosphate compounds on a soil protist, Colpoda inflata (Ciliophora, Colpodidae)

Many investigations on protists indicate that they play an important role in agricultural soils. We have tested the effects of three organophosphate (OP) pesticides, basudin, cidial, and fenix, on the soil ciliate Colpoda inflata, and examined its viability, fission rate, ability to excyst and extrude macronuclear chromatin into cytoplasm. Exposure to these OPs caused a dose-dependent effect on cell viability, and significantly reduced the mean fission rate at a concentration of 1/10(5) v/v. After exposure of resting cysts to 1/10(5) v/v or 1/10(6) v/v concentrations of basudin or cidial, the number of excysted cells was significantly lower than that of the controls. Conversely, exposure to a 1/10(5) v/v fenix concentration did not affect excystment and exposure to 1/10(6) v/v was found to promote excystment. Moreover, exposure to these OPs (1/10(4) v/v or 1/10(5) v/v) interferred with the ability to extrude macronuclear chromatin. The median lethal concentration in 60 min for each OPs tested was at least a hundred times lower than the doses recommended by the manufacturer. Finally, as the inhibition of cholinesterase (ChE) activity is the first target of OPs, the presence of ChE activity was checked in C. inflata. Three ChE activities were found, hydrolyzing the substrates acetyl-beta-methyl thiocholine iodide, propionyl thiocholine iodide and butyryl thiocholine iodide, that appeared to be very low and not inhibited by OP-exposure.     

Pesticide exposure and serum organochlorine residuals among testicular cancer patients and healthy controls

The incidence of testicular cancer (TC) has been increasing worldwide during the last decades. The reasons of the increase remains unknown, but recent findings suggest that organochlorine pesticides (OPs) could influence the development of TC. A hospital-based case-control study of 50 cases and 48 controls was conducted to determine whether environmental exposure to OPs is associated with the risk of TC, and by measuring serum concentrations of OPs, including p,p’-dichlorodiphenyldichloroethylene (p,p’-DDE) isomer and hexachlorobenzene (HCB) in participants. A significant association was observed between TC and household insecticide use (odds ratio [OR] = 3.01, 95 % CI: 1.11-8.14; OR_adjusted = 3.23, 95 % CI: 1.15-9.11). Crude and adjusted ORs for TC were also significantly associated with higher serum concentrations of total OPs (OR = 3.15, 95 % CI: 1.00-9.91; OR_adjusted = 3.34, 95 % CI: 1.09-10.17) in cases compared with controls. These findings give additional support to the results of previous research that suggest that some environmental exposures to OPs may be implicated in the pathogenesis of TC.     

Screening of organophosphorus compounds and their distribution in various indoor environments

Twelve organophosphorus compounds (OPs), which are used for diverse purposes (e.g. as plasticizers and flame retardants), were analysed in settled house dust from 15 indoor environments and in wipe test samples from computer screens and covers. Seven of the substances analysed dominated Swedish imports of OPs in 1999, six of these are also listed as EU High Production Volume Chemicals. Eight of the substances were found in all samples. Tris(2-butoxyethyl)phosphate was the most abundant in most of the samples, with levels ranging from 0.014 to 5.3 g/kg followed by tris(2-chloroethyl)phosphate, tris(chloropropyl)phosphate and tris(1,3-dichloropropyl)phosphate. In wipe test samples from computers, triphenyl phosphate proved to be the main component of the OPs analysed (4.0 microg/m2). Potential sources of these compounds include, inter alia, floor polish, polyvinylchloride floor coverings, upholstery and plastic products. The distribution patterns of the OPs differed between the sites and generally reflected the building materials and consumer products used in their vicinity.     

Oxidation of organophosphorus pesticides for the sensitive detection by a cholinesterase-based biosensor

A potentiometric flow injection-type biosensor developed in our laboratory was used for the determination of organophosphorus pesticides (OPs). The principle of the biosensor is that the degree of inhibition of a sensor enzyme by an OP is dependent on the concentration of the pesticide. The sensor system consisted of a reactor with acetylcholinesterase (AChE) immobilized on a controlled pore glass and a detector with a tubular H(+)-selective membrane electrode. In order to examine the possibility of enhancing the sensitivity of the sensor by converting OPs to oxidized forms (stronger inhibitors), a comparison of the degree of enzyme inhibition by OPs at 10(-6) M before and after their oxidation was made. All of the ten pesticides tested exhibited greater inhibitory power toward the sensor enzyme following oxidation. All of the oxidized pesticides at 10(-6) M inhibited the sensor enzyme to a considerable degree, demonstrating the utility of the developed method for the class-specific determination of OPs. A calibration curve for diazinon, over the concentration range of 10(-11)-10(-4) M, was obtained. The lower detection limit was 2 x 10(-10) M. Treatment of the inhibited enzyme with pyridine-2-aldoxime restored the enzyme to near full activity, allowing repeated use of the sensor.     

Development of IC-ELISA for detection of organophosphorus pesticides in water

Diethyl (carboxymethyl) phosphonate (DECP) was used as the hapten to develop an indirect competitive enzyme-linked immunosorbent assay (IC-ELISA) for detecting organophosphorus pesticides (OPs). Conjugator of DECP with bovin serum albumin (BSA) was used as the immunogen for producing the polyclonal antibodies (PcAbs). Three antisera were obtained after the immune procedure. Characterization studies of the PcAbs indicated that the titer of antiserum-1 was highest in 3 antisera, and antiserum-1 had high affinity and specificity to the parathion, dichlorvos and pirimiphos. The IC-ELISA showed an IC50 of 0.428 micro g/mL with a detection limit of 0.0125 micro g/mL to parathion. The assay also indicated that the IC50 values of pirimiphos and dichlorvos were 0.331 micro g/mL and 1.25 micro g/mL respectively, and the detection limits of pirimiphos and dichlorvos were 0.0116 micro g/mL and 0.048 micro g/mL respectively. Recoveries of parathion, pirimiphos and dichlorvos spiked into water samples ranged from 90% to 160%. The results indicated that the ELISA could be a convenient and supplemental analytical tool for monitoring OPs residues in environmental water samples.     

Dissipation pathways of organic pollutants during the composting of organic wastes

The organic pollutants (OPs) present in compostable organic residues can be recovered in the final composts leading to environmental impacts related to their use in agriculture. However, the composting process may contribute to their partial dissipation that is classically evaluated through the concentration decrease in extractable OPs, without identification of the responsible mechanisms as mineralization or stabilization of OP as non-extractable residues (NER) or bound residues. The dissipation of four (14)C-labeled OPs (fluoranthene; 4-n-nonylphenol, NP; sodium linear dodecylbenzene sulfonate, LAS; glyphosate) was assessed during composting of sewage sludge and green waste. The dissipation of LAS largely resulted from its mineralization (51% of initial LAS), whereas mineralization was intermediate for NP (29%) and glyphosate (24%), and negligible for fluoranthene. The NER pathway mostly concerned NP and glyphosate, with 45% and 37% of the recovered (14)C being found as NER at the end of composting, respectively. In the final composts, the proportions of water soluble residues of OPs considered as readily available were <11% of recovered (14)C-OPs. However, most fluoranthene remained solvent extractable (72%) and potentially available, whereas only 18% of glyphosate and less than 7% of both NP and LAS remained solvent extractable in the final compost.     

Cytotoxicity and DNA damage of five organophosphorus pesticides mediated by oxidative stress in PC12 cells and protection by vitamin E

Previous studies have demonstrated that pesticides could induce cytotoxicity and genotoxicity in vivo and in vitro, and that oxidative stress may be an important factor involved. However, investigations comparing the capability of different organophosphorous (OP) compounds to induce cytotoxicity, genotoxicity and oxidative stress are limited. Hence, the aim of this paper was to access the cytotoxic and genotoxic effects of five OPs or metabolites, Acephate (ACE), Methamidophos (MET), Chloramidophos (CHL), Malathion (MAT) and Malaoxon (MAO), and to clarify the role of oxidative stress, using PC12 cells. The results demonstrated that MET, MAT and MAO caused significant inhibition of cell viability and increased DNA damage in PC12 cells at 40 mg L(-1). MAO was more toxic than the other OPs. ACE, MET, MAT and MAO increased the levels of intracellular reactive oxygen species (ROS) and malondialdehyde (MDA), and decreased the activity of superoxide dismutase (SOD), catalase (CAT) and glutathione (GSH) at 20 mg L(-1) and 40 mg L(-1) to different degrees. Pre-treatment with vitamin E(600 μM)caused a significant attenuation in the cytotoxic and genotoxic effect; pre-treatment reversed subsequent OP-induced elevation of peroxidation products and the decline of anti-oxidant enzyme activities. These results indicate that oxidative damage is likely to be an initiating event that contributes to the OP-induced cytotoxicity.     

Cytotoxicity and DNA damage of five organophosphorus pesticides mediated by oxidative stress in PC12 cells and protection by vitamin E

Previous studies have demonstrated that pesticides could induce cytotoxicity and genotoxicity in vivo and in vitro, and that oxidative stress may be an important factor involved. However, investigations comparing the capability of different organophosphorous (OP) compounds to induce cytotoxicity, genotoxicity and oxidative stress are limited. Hence, the aim of this paper was to access the cytotoxic and genotoxic effects of five OPs or metabolites, Acephate (ACE), Methamidophos (MET), Chloramidophos (CHL), Malathion (MAT) and Malaoxon (MAO), and to clarify the role of oxidative stress, using PC12 cells. The results demonstrated that MET, MAT and MAO caused significant inhibition of cell viability and increased DNA damage in PC12 cells at 40 mg L^?1. MAO was more toxic than the other OPs. ACE, MET, MAT and MAO increased the levels of intracellular reactive oxygen species (ROS) and malondialdehyde (MDA), and decreased the activity of superoxide dismutase (SOD), catalase (CAT) and glutathione (GSH) at 20 mg L^?1 and 40 mg L^?1 to different degrees. Pre-treatment with vitamin E(600 μM)caused a significant attenuation in the cytotoxic and genotoxic effect; pre-treatment reversed subsequent OP-induced elevation of peroxidation products and the decline of anti-oxidant enzyme activities. These results indicate that oxidative damage is likely to be an initiating event that contributes to the OP-induced cytotoxicity.     

Development of IC-ELISA for detection of organophosphorus pesticides in water

Diethyl (carboxymethyl) phosphonate (DECP) was used as the hapten to develop an indirect competitive enzyme-linked immunosorbent assay (IC-ELISA) for detecting organophosphorus pesticides (OPs). Conjugator of DECP with bovin serum albumin (BSA) was used as the immunogen for producing the polyclonal antibodies (PcAbs). Three antisera were obtained after the immune procedure. Characterization studies of the PcAbs indicated that the titer of antiserum-1 was highest in 3 antisera, and antiserum-1 had high affinity and specificity to the parathion, dichlorvos and pirimiphos. The IC-ELISA showed an IC₅₀ of 0.428 μ g/mL with a detection limit of 0.0125 μ g/mL to parathion. The assay also indicated that the IC₅₀ values of pirimiphos and dichlorvos were 0.331 μ g/mL and 1.25 μ g/mL respectively, and the detection limits of pirimiphos and dichlorvos were 0.0116 μ g/mL and 0.048 μ g/mL respectively. Recoveries of parathion, pirimiphos and dichlorvos spiked into water samples ranged from 90% to 160%. The results indicated that the ELISA could be a convenient and supplemental analytical tool for monitoring OPs residues in environmental water samples.     

Structural elucidation of main ozonation products of the artificial sweeteners cyclamate and acesulfame

Purpose  

The two artificial sweeteners cyclamate (CYC) and acesulfame (ACE) have been detected in wastewater and drinking water treatment plants. As in both facilities ozonation might be applied, it is important to find out if undesired oxidation products (OPs) are formed.     

Preliminary examination of contaminant loadings in farmed salmon, wild salmon and commercial salmon feed

This pilot study examined five commercial salmon feeds, four farmed salmon (one Atlantic, three chinooks) and four wild salmon (one chinook, one chum, two sockeyes) from the Pacific Coast for PCBs (112 congeners), polybrominated diphenylethers (PBDEs - 41 congeners), 25 organochlorine pesticides (OPs), 20 polycyclic aromatic hydrocarbons (PAHs), and methyl and inorganic mercury. The farmed salmon showed consistently higher levels of PCBs, PBDEs, OPs (except toxaphene) than the wild salmon. The mean concentrations in pg/g were 51,216 vs 5302 for total PCBs; 2668 vs 178 for total PBDEs; 41,796 vs 12,164 for total OPs (except toxaphene). The farmed salmon levels are likely a consequence of the elevated level of contamination found in the commercial salmon feed (mean concentrations in pg/g were 65,535 for total PCBs; 1889 for total BPDEs; 48,124 for total OPs except toxaphene). Except for a single high wild chinook value, PAHs were highest in the feed samples followed by the farmed fish and the three other wild fish. The Bio-Oregon-1996 feed of hatchery origin showed a level of PAHs ten times higher than any other feed. The genotoxic implications of such a high PAH level are considered for juvenile chinook salmon. Toxaphene and methyl mercury concentrations were not notably different between the wild and farmed salmon. There was no clear low contaminant brand of salmon feed. The human health implications of eating farmed salmon are considered from the perspective of the current WHO and Health Canada (2000) tolerable daily intake (TDI) values for PCBs. Based on a TDI of 1 pg TEQ/kg bw/day, this analysis indicated a safety concern for individuals who on a regular weekly basis consume farmed salmon produced from contaminated feed.