Organochlorine and organophosphoric insecticides, herbicides and heavy metals residue in industrial wastewaters in Cyprus

Determination of lindane in surface water samples and its degradation by hydrogen peroxide and persulfate assisted TiO2-based photocatalysis

Organochlorine pesticides (OCPs) have been used extensively as insecticides and herbicides. This study investigates the occurrence of lindane in surface water from the Peshawar valley (i.e., Peshawar, Charsadda, Nowshera, Mardan and Swabi districts of Khyber Pakhtunkhwa, Pakistan). Out of 75 samples tested (i.e., 15 samples from each district), 13 samples (including 2 from Peshawar, 3 from Charsadda, 4 from Nowshera, 1 from Mardan, and 3 from Swabi) are found to be contaminated with lindane. Overall, the detection frequency is 17.3%. The maximum concentration of lindane is detected in a water sample from Nowshera and found to be 2.60 μg L^-1. Furthermore, the degradation of lindane in the water sample from Nowshera, containing the maximum concentration, is investigated by simulated solar-light/TiO₂ (solar/TiO₂), solar/H₂O₂/TiO₂ and solar/persulfate/TiO₂ photocatalysis. The degradation of lindane by solar/TiO₂ photocatalysis is 25.77% after 10 h of irradiation. The efficiency of the solar/TiO₂ process is significantly increased in the presence of 500 μM H₂O₂ and 500 μM persulfate (PS) (separately), represented by 93.85 and 100.00% lindane removal, respectively. The degradation efficiency of lindane is lower in natural water samples as compared to Milli-Q water, attributed to water matrix effect. Moreover, the identification of degradation products (DPs) shows that lindane follows similar degradation pathways in natural water samples as the one in Milli-Q water. The results show that the occurrence of lindane in surface waters of Peshawar valley is a matter of great concern for human beings and the environment. Interestingly, H₂O₂ and PS assisted solar/TiO₂ photocatalysis is an effective method for the removal of lindane from natural water.

Evaluation and remediation protocol of selected organochlorine pesticides and heavy metals in industrial wastewater using nanoparticles (NPs) in Nigeria

Limited knowledge of the level of contaminants in industrial wastewater within the Nigerian states together with the global challenge of water supply have compelled our investigation into the analyses and removal of organochlorine pesticides (OCPs) and heavy metal contents in industrial wastewater. Wastewater samples were collected from 13 industries across five states in Nigeria. The OCPs content of the samples was extracted, cleaned up and analysed using gas chromatography-mass spectrometry. The results indicate that the mean concentrations of the OCPs in the effluent samples ranged from 1.76 ng L^-1 (Dieldrin) to 0.89 ng L^-1 (endrin). Cadmium (Cd), chromium (Cr) and lead (Pb) were evaluated in all the effluent water samples. The results show that the average concentrations of the heavy metal ions in the effluent samples ranged from 0.008 ± 0.003 mg L^-1 (Cd) to 2.215 ± 0.841 mg L^-1 (Pb). For the removal of the identified contaminants, biomagnetite nanoparticles (BioMag), magnetite nanoparticles (MagNPs), biomagnetite-CMC nanocomposite (BioMag-CMC) and magnetite-CMC nanocomposite (MagNPs-CMC) were synthesised and characterised using Braunauer-Emmett-Teller (BET), Fourier transform infrared (FTIR) spectroscopy, X-ray diffraction (XRD) and high resolution-transmission electron microscopy (HR-TEM). This study demonstrates the successful application of nanoparticles (NPs) and nanocomposites in the removal of OCPs and heavy metal ions in industrial effluents. The routine assessment and continuous removal become important to attain a state of clean and healthy aquatic ecosystem due to rapid industrial and technological advances.

Survey of organochlorine-tolerant culturable mycota from contaminated soils, and 2,4-D removal ability of Penicillium species in synthetic wastewater

Agrochemical wastewater, which is produced by the extensive use of herbicides, has become a serious environmental pollutant. In this study, culturable mycota were isolated from soils contaminated with herbicides 2,4-dichlorophenoxyacetic acid (2,4-D) and 4-chloro-2-methylphenoxyacetic acid (MCPA), and their ability to tolerate and remove 2,4-D was assessed. The mycota were isolated on solid medium supplemented with 10 mmol L^-1 of MCPA or 2,4-D. Tolerance and removal assays were performed in synthetic wastewater, and removal was quantified by HPLC-UV and MS/MS. Fusarium spp., Aspergillus spp., and Penicillium spp. were the most frequently isolated genera. Six Penicillium strains were able to tolerate up to 25 mmol L^-1 of 2,4-D. Within this group, two P. crustosum strains (RCP4 and RCP13) degraded more than 50% of the 2,4-D in the medium during the first 7 days of incubation. Removal percentages reached 54% for RCP4 and 75% for RCP13 after 14 days. These two strains, therefore, could potentially be considered for the design of bioaugmentation strategies aimed at reducing contamination by 2,4-D in wastewater.

Metabolomic analysis for combined hepatotoxicity of chlorpyrifos and cadmium in rats

Pesticides and heavy metals are widespread environmental pollutants. Although the acute toxicity of organophosphorus pesticide chlorpyrifos (CPF) and toxic heavy metal cadmium (Cd) is well characterized, the combined toxicity of CPF and Cd, especially the hepatotoxicity of the two chemicals with long-term exposure at a low dose, remained unclear. In this study, we investigated the toxicity in the liver of rats upon subchronic exposure to CPF and Cd at environmentally relevant doses. Rats were given three different doses (1/135 LD₅₀, 1/45 LD₅₀ and 1/15 LD₅₀) of CPF and Cd as well as their mixtures by oral gavage for 90days. After treatment, the liver tissues were subjected to histopathological examination and biochemical analysis. Gas chromatography-mass spectrometry (GC-MS) was used to analyze the metabolomic changes in the rat liver upon CPF, Cd and their mixtures treatment. The results showed that CPF and Cd-induced oxidative damage and disrupted energy, amino acid, and fatty acid metabolism in the liver. Eleven biomarkers in liver were identified for CPF-, Cd-, and their mixture-treated rats. Three metabolites, i.e., butanedioic acid, myo-inositol, and urea, were identified as unique biomarkers for the mixture-treated rats. Moreover, we found that Cd could accelerate the metabolism of CPF in the liver when given together to the rats, which may lead to the potential antagonistic interaction between CPF and Cd. In conclusion, our results indicated that even at environmentally relevant doses, CPF and Cd could disrupt the liver metabolism. In addition, the accelerated metabolism of CPF by Cd may lead to their potential antagonistic interaction.

Integrated wetlands for food production

The widespread use of compound pelleted feeds and chemical fertilizers in modern food production contribute to a vast amount of residual nutrients into the production system and adjacent ecosystem are major factors causing eutrophication. Furthermore, the extensive development and application of chemical compounds (such as chemical pesticides, disinfectants and hormones used in enhancing productivity) in food production process are hazardous to the ecosystems, as well as human health. These unsustainable food production patterns cannot sustain human living in the long run. Wetlands are perceived as self-decontamination ecosystems with high productivities. This review gives an overview about wetlands which are being integrated with food production processes, focusing on aquaculture.

Pesticides in Ichkeul Lake-Bizerta Lagoon Watershed in Tunisia: use, occurrence, and effects on bacteria and free-living marine nematodes

This study aimed to identify the most commonly used agricultural pesticides around Ichkeul Lake-Bizerta Lagoon watershed. First survey of pesticide use on agricultural watershed was performed with farmers, Regional Commissioner for Agricultural Development, and pesticide dealers. Then, sediment contamination by pesticides and response of benthic communities (bacteria and free-living marine nematode) were investigated. The analysis of 22 active organochlorine pesticides in sediments was performed according to quick, easy, cheap, effective, rugged, and safe (QuEChERS) method, biodiversity of indigenous bacterial community sediment was determined by terminal restriction fragment length polymorphism (T-RFLP), and free-living marine nematodes were counted. The results of the field survey showed that iodosulfuron, mesosulfuron, 2,4-dichlorophenoxyacetic acid (2,4 D), glyphosate, and fenoxaprops were the most used herbicides, tebuconazole and epoxiconazole the most used fungicides, and deltamethrin the most used insecticide. Sixteen organochlorine pesticide compounds among the 22 examined were detected in sediments up to 2 ppm in Ichkeul Lake, endrin, dieldrin, and hexachlorocyclohexane being the most detected molecules. The most pesticide-contaminated site in the lake presented the higher density of nematode, but when considering all sites, no clear correlation with organochlorine pesticide (OCP) content could be established. The bacterial community structure in the most contaminated site in the lake was characterized by the terminal restriction fragments (T-RFs) 97, 146, 258, 285, and 335 while the most contaminated site in the lagoon was characterized by the T-RFs 54, 263, 315, 403, and 428. Interestingly, T-RFs 38 and 143 were found in the most contaminated sites of both lake and lagoon ecosystems, indicating that they were resistant to OCPs and able to cope with environmental fluctuation of salinity. In contrast, the T-RFs 63, 100, 118, and 381 in the lake and the T-RFs 40, 60, 80, 158, 300, 321, and 357 in the lagoon were sensitive to OCPs. This study highlighted that the intensive use of pesticides in agriculture, through transfer to aquatic ecosystem, may disturb the benthic ecosystem functioning of the protected area. The free-living marine nematodes and bacterial communities represent useful proxy to follow the ecosystem health and its capacity of resilience.

Dissipation kinetics and residue of LH-2010A in cucumber and soil under greenhouse condition

LH-2010A is a newly developed fungicide with novel mode of action in the treatment of cucurbit downy mildew. Dissipation kinetics and residue levels of LH-2010A in cucumber were investigated using a QuEChERS method with GC-ECD. Field trials were constructed at three different sites in China in 2013 and 2014. The average recoveries of LH-2010A in fortified samples were between 94.0 and 106.2% for cucumber and between 84.4% and 98.7% for soil, with relative standard deviations within 3%. The dissipation rate of LH-2010A residue was evaluated assuming a pseudo first-order kinetics. The half-lives of LH-2010A were 2.8-4.2 days and 6.3-9.4 days in cucumber and soil samples, respectively. The terminal residues in cucumber were 0.077-0.207 mg/kg and 0.109-0.307 mg/kg on the first day after spray at the recommended dosage and 1.5 times of the recommended dosage, respectively. Using this rapid and sensitive method, we determined the dissipation kinetics and residue level of HL-2010A in cucumber. The suggested MRL value of HL-2010A in cucumber is 0.5 mg/kg. The research would provide guidance for proper and safe use of this newly developed fungicide in cucumber in greenhouse ecosystems.

Synergistic hepatotoxicity by cadmium and chlorpyrifos: disordered hepatic lipid homeostasis

Due to its extensive application, chlorpyrifos (CPF) has contaminated a diverse range of environmental substrates, fruits and vegetables. A number of studies have suggested that CPF may incur adverse effects on human health, including neurotoxicity, hepatotoxicity and endocrine disruption. Additionally, cadmium (Cd) is one of the most prevalent environmental heavy metals, as a result of considerable use in a wide spectrum of industrial fields. Exposure to Cd can cause several lesions in various organs, including the liver, kidneys and lungs. CPF and Cd often co-exist in the environment, food and crops, however, their joint exposure and potential synergistic toxicity are largely neglected and unrecognized. Our previous study characterized an interaction between CPF and Cd, which may occur via bonding between Cd2+ and the nitrogen atom in the pyridine ring of CPF, or the chelation between one Cd2+ and two CPF molecules. Our previous study also identified increased hepatotoxicity induced by CPF and Cd together compared with the individual compounds. In the present study, the effects of the concomitant exposure of CPF and Cd on lipid metabolism in hepatocytes was investigated. The results demonstrated an accumulation of lipids in hepatocytes, induced by the CPF and Cd complex, which was fundamentally distinct from its parental chemicals. Notably, the molecular mechanism by which the CPF-Cd complex significantly induced hepatic lipogenesis was revealed, elevating the concentrations of sterol regulatory element-binding protein-1 and fatty acid synthase. These findings pave the way for future studies in recognizing synergistic biological effects between pollutants.

Incidence and time trends of cancer in Cyprus over 11 years (1998-2008)

Cyprus maintains a population-based cancer registry that allows for in-depth study of cancer in a culturally and environmentally unique setting. Using 11 years of collected data (1998-2008), we present the first comprehensive analysis of cancer in Cyprus. We calculated gender-specific, world age-adjusted incidence rates and time trends for the 26 most incident cancers. This study revealed that overall world age-standardized rates among men increased from 195.4 cases per 100,000 in 1998-2002 to 239.0 cases per 100,000 in 2006-2008. For the entire 11-year period, prostate, lung, colorectal and bladder cancers were the most incident cancers among men. Among women, the overall world age-standardized rate increased from 180.6 cases per 100,000 in 1998-2002 to 217.1 cases per 100,000 in 2006-2008. Over the entire period, breast, colorectal, uterine and thyroid cancers were the most incident cancers in women. There were 16 sex-specific cancers showing statistically significantly increasing incidence trends over the study period and no types for which the rate was significantly decreasing. Thyroid cancer illustrated rapid increases in rates. Results were compared to other Mediterranean European registries using the Cancer Incidence in 5 Continents reports for 1997-2002. Overall cancer incidence in Cyprus is lower than that of many southern Mediterranean countries, and given the known environmental risk factors in Cyprus, the low rate of lung cancer is especially interesting. The epidemiologic patterns reported in this study open the door for future etiologic studies to elucidate the role of environmental and lifestyle factors in this population and highlight opportunities for cancer prevention and control.

Cancer trends and risk factors in Cyprus

Cyprus, a European Union member state, is a small island in the Mediterranean with a population approaching 900,000 people. Cancer is the second leading cause of death; more therapeutic options for any patient with the disease are available in a central oncology centre in the capital of the island (Nicosia) and fewer therapeutic options (e.g. chemotherapy and hormone therapy only) in a few other public hospitals. Palliative care is offered in several hospices and hospitals, although the field needs improvement. With regards to screening, a national breast cancer screening programme has been in place countrywide since 2007 and is offered free of charge to women between the ages of 50 and 69 years, while colorectal and prostate cancer screening is performed on an individual basis (a pilot programme for colorectal cancer screening was recently initiated). Genetic testing is available for breast and colon cancer. To improve understanding of the causes of cancer in the country, a cancer research centre was established in 2010 (Mediterranean Centre for Cancer Research). Recent epidemiologic work has revealed increasing cancer trends in Cyprus; prostate cancer is the most common in men and breast cancer is the most common in women. Interestingly, thyroid cancer incidence in women has been rising from 1998 to 2008. Cancer of the colon and rectum is also on the rise affecting both sexes. Overall, cancer incidence in Cyprus is lower than other EuroMed countries with similar lifestyle and geography.

Environmentally friendly system for the degradation of multipesticide residues in aqueous media by the Fenton's reaction

A Fenton oxidation system employing zero-valent iron (whose source was swarf, a residue of metallurgical industries, in powder form) and hydrogen peroxide for the treatment of an aqueous solution with six pesticides was developed, and the effect of the iron metal content, pH, and hydrogen peroxide concentration was evaluated. The characterization of the aqueous solution resulted in: pH 5.6, 105 mg L(-1) of dissolved organic carbon, and 44.6 NTU turbidity. In addition, the characterization of the swarf by FAAS and ICP-MS showed 98.43 ± 7.40 % of zero-valent iron. The removal was strongly affected by the content of iron metal, pH, and hydrogen peroxide concentration. The best degradation conditions were 2.0 g swarf, pH 2.0, and 5 mmol L(-1) H2O2. At the end of the treatment, the pesticide degradation ranged from 60 to 100%, leading to 55% mineralization. Besides, all hydrogen peroxide was consumed and the determination of total dissolved iron resulted in 2 mg L(-1). Thus, the advantages of this system are rapid degradation (up to 20 min), high-degradation rates, simple handling, and low cost.

Occurrence and removal efficiency of pesticides in sewage treatment plants of four Mediterranean River Basins

Removal of contaminants in the sewage treatment plants (STPs) can be incomplete causing their release to the environment. In this paper, the results of an extensive survey on more than 40 pesticides carried out in 2010 and 2011 in 16 STPs of Ebro, Guadalquivir, Jucar and Llobregat Rivers (Spain) are presented. In 2010, of 43 analytes screened, 29 were detected in influent and 28 in effluent samples, meanwhile in 2011, of 50 analytes, 33 and 34 were detected, respectively. Pesticides were in the range of 0.33 ng L(-1) (terbumeton, 2011)-2526.05 ng L(-1) (diuron, 2010) for influent and 0.25 ng L(-1) (terbumeton, 2011)-2821.12 ng L(-1) (carbendazim, 2011) for effluent. Regarding the sludge samples, 11 pesticides were detected in 2010 and 24 in 2011 at concentrations up to 25667.34 ng g(-1) dry weight (dw). Removal efficiencies showed that, in 2010, the elimination ranged from -810% (chlorfenvinphos) to 93% (dimethoate), and in 2011, from -4575% (diazinon) to 97% (chlorfenvinphos). All these data confirm that most of the pesticides are only partially eliminated during the secondary and even tertiary treatments, commonly used in STPs, suggesting that they can be a focal point of contamination to the rivers.

Spatial variations in polycyclic aromatic hydrocarbons concentrations at surface sediments from the Cyprus (Eastern Mediterranean): relation to ecological risk assessment

The objective of the present study was to evaluate the distribution, sources, origins, and environmental risk assessment of polycyclic aromatic hydrocarbons (16 US EPA priority pollutants) pollution in 23 surface sediments from Cyprus coast. The mean total polycyclic aromatic hydrocarbons (PAHs) concentrations in the sediments from Gemi Konagi, Girne and Gazi Magusa areas were found 47, 52 and 50 ng/g, respectively. Molecular ratios and principle component analysis indicated that PAH pollution originated mainly from fossil sources, with higher pyrolytic contributions. The 2-3 ring PAHs were dominant in Cyprus sediments. Concentrations of PAHs observed in this study were compared with available soil quality guidelines and the concentrations were lower than the guideline values. The guideline values suggested that the Cyprus sediments were likely to be not contaminated by toxic PAH compounds.

Characterization of the interaction between cadmium and chlorpyrifos with integrative techniques in incurring synergistic hepatoxicity

Mixture toxicity is an important issue for the risk assessment of environmental pollutants, for which an extensive amount of data are necessary in evaluating their potential adverse health effects. However, it is very hard to decipher the interaction between compounds due to limited techniques. Contamination of heavy metals and organophosphoric insecticides under the environmental and biological settings poses substantial health risk to humans. Although previous studies demonstrated the co-occurrence of cadmium (Cd) and chlorpyrifos (CPF) in environmental medium and food chains, their interaction and potentially synergistic toxicity remain elusive thus far. Here we integrated the approaches of thin-layer chromatography and (1)H NMR to study the interaction between Cd(2+) and CPF in inducing hepatoxicity. A novel interaction was identified between Cd(2+) and CPF, which might be the bonding between Cd(2+) and nitrogen atom in the pyridine ring of CPF, or the chelation formation between one Cd(2+) and two CPF molecules. The Cd-CPF complex was conferred with distinct biological fate and toxicological performances from its parental components. We further demonstrated that the joint hepatoxicity of Cd ion and CPF was chiefly due to the Cd-CPF complex-facilitated intracellular transport associated with oxidative stress.

Systematic study of the contamination of wastewater treatment plant effluents by organic priority compounds in Almeria province (SE Spain)

The occurrence of priority organic pollutants in wastewater (WW) effluents was evaluated in a semi-arid area, characterized by a high agricultural and tourism activity, as Almeria province (Southeastern Spain). Twelve wastewater treatment plants (WWTPs) were sampled in three campaigns during 2011, obtaining a total of 33 WW samples, monitoring 226 compounds, including pesticides, polycyclic aromatic hydrocarbons (PAHs), phenolic compounds and volatile organic compounds (VOCs). Certain banned organochlorine pesticides such as aldrin, pentachlorobenzene, o,p'-DDD and endosulfan lactone were found, and the most frequently detected pesticides were herbicides (diuron, triazines). PAHs and VOCs were also detected, noting that some of these pollutants were ubiquitous. Regarding phenolic compounds, 4-tertoctylphenol was found in all the WW samples at high concentration levels (up to 89.7 μg/L). Furthermore, it was observed that WW effluent samples were less contaminated in the second and third sampling periods, which corresponded to dry season. This evaluation revealed that despite the WW was treated in the WWTP, organic contaminants are still being detected in WW effluents and therefore they are released into the environment. Finally the risk of environmental threat due to the presence of some compounds in WWTP effluents, especially concerning 4-tertoctylphenol must be indicated.

Organochlorine pesticides removal from wastewater by pine bark adsorption after activated sludge treatment

Pesticides have been responsible for strong environmental impacts, mainly due to their persistence in the environment. Removal technologies are usually combined, because degradation of organic matter is needed prior to a tertiary treatment to guarantee pesticides elimination to levels below legal limits (normally 0.1 microg L(-1)). Pine bark was studied as an alternative to activated carbon, for organochlorine pesticides removal. A combination of technologies based on biodegradation with activated sludge followed by pine bark adsorption treatment was used for lindane (LIN) and heptachlor (HEP) removal from contaminated waters. Pesticides were quantified throughout the process by GC-ECD preceded by solid-phase microextraction (SPME). An experimental set-up was maintained for 4 months, by feeding a standard solution with pesticides concentration of 1 microg L(-1) each and known organic matter (Chemical Oxygen Demand, COD, -563 mg O2 L(-1)) on a daily basis. COD suffered a reduction of about 81% in the biological step and no increase was detected in the subsequent adsorption treatment. Overall removal efficiency was 76.6% and above 77.7% for LIN and HEP, respectively.

Characterization of the metabolically modified heavy metal-resistant Cupriavidus metallidurans strain MSR33 generated for mercury bioremediation

Background

Mercury-polluted environments are often contaminated with other heavy metals. Therefore, bacteria with resistance to several heavy metals may be useful for bioremediation. Cupriavidus metallidurans CH34 is a model heavy metal-resistant bacterium, but possesses a low resistance to mercury compounds.

Methodology/Principal Findings

To improve inorganic and organic mercury resistance of strain CH34, the IncP-1β plasmid pTP6 that provides novel merB, merG genes and additional other mer genes was introduced into the bacterium by biparental mating. The transconjugant Cupriavidus metallidurans strain MSR33 was genetically and biochemically characterized. Strain MSR33 maintained stably the plasmid pTP6 over 70 generations under non-selective conditions. The organomercurial lyase protein MerB and the mercuric reductase MerA of strain MSR33 were synthesized in presence of Hg²⁺. The minimum inhibitory concentrations (mM) for strain MSR33 were: Hg²⁺, 0.12 and CH₃Hg⁺, 0.08. The addition of Hg²⁺ (0.04 mM) at exponential phase had not an effect on the growth rate of strain MSR33. In contrast, after Hg²⁺ addition at exponential phase the parental strain CH34 showed an immediate cessation of cell growth. During exposure to Hg²⁺ no effects in the morphology of MSR33 cells were observed, whereas CH34 cells exposed to Hg²⁺ showed a fuzzy outer membrane. Bioremediation with strain MSR33 of two mercury-contaminated aqueous solutions was evaluated. Hg²⁺ (0.10 and 0.15 mM) was completely volatilized by strain MSR33 from the polluted waters in presence of thioglycolate (5 mM) after 2 h.

Conclusions/Significance

A broad-spectrum mercury-resistant strain MSR33 was generated by incorporation of plasmid pTP6 that was directly isolated from the environment into C. metallidurans CH34. Strain MSR33 is capable to remove mercury from polluted waters. This is the first study to use an IncP-1β plasmid directly isolated from the environment, to generate a novel and stable bacterial strain useful for mercury bioremediation.