Presence Of Organochlorine Pesticides Research Articles

Changes in Adipose Tissue and Circulating Concentrations of Persistent Organic Pollutants in Midlife Women.

Polychlorinated biphenyls (PCBs) and organochlorine pesticides (OCPs) are persistent organic pollutants (POPs) that bioaccumulate in adipose tissue. We investigated the relationship between change in central adiposity and changes in circulating concentrations of POPs over a 12-year period during the midlife. Serum concentrations of 34 PCBs and 19 OCPs were measured at four time points (1999/2000, 2002/03, 2005/06, 2009/11) in a cohort of midlife women, the Study of Women's Health Across the Nation. Linear mixed models were used to test the association between a change in waist circumference and a change in serum POP concentrations. Sixty-five women contributed 181 PCB observations. Fifty-nine women contributed 151 OCP observations. After adjustment for covariates (study site, race and ethnicity, age at baseline, parity), a one-inch (2.54 cm) increase in the change in waist circumference between visits was associated with a 4.9% decrease in the change in serum concentration of PCB 194 (95% CI: -8.0%, -1.6%). No associations were observed for other PCB congeners or the presence of OCPs. An increase in the difference in waist circumference over time was not associated with a change in the difference in serum concentrations of PCBs and OCPs except for PCB 194, possibly due to the high lipophilicity.

P18-017-23 The Presence of Organochlorine Pesticides in Breast Milk and the Trajectory of Infant Growth Z-Score Throughout the First Year of Life in a Brazilian Cohort

P18-017-23 The Presence of Organochlorine Pesticides in Breast Milk and the Trajectory of Infant Growth Z-Score Throughout the First Year of Life in a Brazilian Cohort

Polybrominated diphenyl ethers and organochloride pesticides in the organic matter of air suspended particles in Mexico valley: A diagnostic to evaluate public policies

The presence of organochlorine pesticides (OCPs) and polybrominated diphenyl ethers (PBDEs) was analysed in air particulate matter ≤ 2.5 μm (PM2.5) and ≤10 μm (PM10) collected in the Metropolitan Zone of Mexico Valley (MZMV), during 2013 and 2014, respectively. Spatial and seasonal distributions of PM and their organic content named solvent extracted organic matter (SEOM) were determined. PM mass concentration and SEOM/PM ratios were compared with previous studies in 2006 in Mexico City. PM2.5 concentration was like found in 2006, however, PM10 decreased ∼43%. The SEOM/PM10 ratio was kept constant, suggesting a decrease in SEOM as well as PM10 emitted from natural sources, probably as a result of changes in the land use due to urban growth. A decrease ∼50% SEOM/PM2.5 ratio was observed in the same period, linked to adequate strategies and public policies applied by the local and federal governments to control the organic matter emitted from anthropogenic sources.Seven out of sixteen OCPs and five out of six PBDEs were found. The most common POPs were endosulfan I, endosulfan II, endosulfan sulfate, BDE-47 and BDE-99, present on >90% of the sampling days. OCPs in PM2.5 and PBDEs in PM10 showed seasonal variability. Higher PBDEs concentration in both particle sizes were observed at east and southeast of the MZMV, where one of the biggest landfills and wastewater treatment plants are located. OCPs in PM10 were mainly emitted from agricultural areas located to the southwest, southeast and east of the MZMV. OCPs in PM2.5 showed a regional contribution from the north and introduced into the valley. OCP degradation products were dominant over native OCPs, indicating no fresh OCP use. POPs comparison with other cities was made. Agreements and commissions created by the Mexican government reduced OCPs emissions, however, more effort must be made to control PBDE emission sources.

Investigating the presence of emerging and legacy POPs in European domestic air

Presence of organochlorine pesticides (OCPs), polychlorinated biphenyls (PCBs), polybrominated diphenyl ethers (PBDEs) and dechlorane plus (DP) were evaluated in indoor domestic air from four European countries (Belgium, Italy, Spain and Portugal). The main pollutants were hexachlorohexanes (sum of α-, β- and γ-HCH; ΣHCHs) and ΣPCBs (sum of PCB-28, 52, 101, 118, 138, 153 and 180), with median concentrations of 366 and 306 pg/m3, respectively. By decreasing order came hexachlorobenzene (HCB; 130 pg/m3), ΣDDXs (sum of DDTs, DDEs and DDDs; 94.4 pg/m3), ΣPBDEs (sum of BDE-17, 28, 47, 66, 99, 100, 153, 154, 183, 206, 207 and 209; 6.08 pg/m3) and DP (0.30 pg/m3). Lower ΣPCBs and ΣDDXs levels were found at Portuguese homes compared to Belgian, Italian and Spanish households. Italian samples presented also lower ΣHCHs concentrations while Spanish homes revealed higher HCB and BDE-209 indoor air concentrations than those obtained in the other countries. ΣHCHs, ΣDDXs and ΣPBDE levels mirrored lindane, dicofol and Penta-, DecaBDE use, respectively. The influence of building characteristics, surroundings and inhabitants habits on pollutant air concentrations was investigated. Data generated were used to conduct a human exposure assessment for toddlers and adults with median (P50) and upper (P95) concentrations. Results indicated that health risk posed by inhalation of ΣPCBs, ΣHCHs, ΣDDXs, HCB, ΣPBDEs and DP were 2 to 5 orders of magnitude lower than oral Reference Dose (RfD) values, and 90 (PCB-28) and 12 (γ-HCH) times lower than Minimal Risk Levels (MRLs) for toddlers at the worst case scenario.

Dietary habits associated with the presence of organochlorine pesticides in human milk

This study aims to establish the relationship between the consumption of certain foods and the presence of organochlorine pesticides in human milk. A total of 167 samples of breastmilk were collected. Sample analysis was carried out by gas chromatography with electron capture detector. Pesticide concentrations (op’DDT, pp’DDT, pp’DDE, Σ-DDT, HCB, β-HCH) were grouped by consumption level of fish, dairy products, meat, eggs, and seafood and then were compared to each other. The odds ratio (OR) was calculated between the concentration of pesticides (higher and/or lower than median) and the exposure variable (high consumption). The results indicated low median concentrations of HCB, β − HCH, op’DDT and pp’DDT, whose fluctuations and trends between different frequencies of food consumption were not significant. pp’DDE and Σ − DDT values according to the increase in consumption of fish were significantly increased. Women with high fish consumption have a higher risk of high concentrations of pp’DDE and Σ-DDT (OR: high consumption: 5.6 (1.3–23.6). A protective effect was observed in the consumption of dairy products (β-HCH and op’DDT), meat (HCB), and seafood (pp’DDT). These results suggest that it is possible that the consumption of fish, dairy products, meat, and seafood influences the presence of organochlorine pesticides in the studied population.

АНАЛИЗ ХЛОРОРГАНИЧЕСКИХ СОЕДИНЕНИЙ (ХОС) В КОРМАХ ДЛЯ ЦЫПЛЯТ-БРОЙЛЕРОВ МЕТОДОМ ГАЗОЖИДКОСТНОЙ ХРОМАТОГРАФИИ С МАСС- СПЕКТРОМЕТРИЧЕСКИМ ДЕТЕКТОРОМ

The article shows the importance of the study of feed for broiler chickens on the content of organochlorine pesticides. These substances in significant concentrations can disrupt the development of birds and cause mass poisoning. The study of formula feed for broiler chickens «prestart» and «start» by two methodswas conducted: a certified method for the determination of organochlorine pesticides in feed and formula feed (thin layer chromatography) and a method for detecting pesticides not certified for feed (gas-liquid chromatography with mass spectrometer detector). During the experiment, the presence of organochlorine pesticides in several formulafeed samples was revealed.

Study of organochlorine pesticides and heavy metals in soils of the Juarez valley: an important agricultural region between Mexico and the USA

The Juarez Valley is an important agricultural region in northern Mexico, conveniently organized into three modules (I to III). For decades, their soils have been exposed to organochlorine pesticides (OCPs) and also have been irrigated with wastewaters, which may contain heavy metals. Nowadays, there is very limited information regarding the presence of OCPs and heavy metals in these soils. Thus, the aim of this study was to diagnose these soils for OCPs and heavy metal content by using gas chromatography coupled with electron micro-capture detector and atomic absorption spectrometry, respectively. The results indicated that 4,4'-dichlorodiphenyldichloroethylene and 4,4'-dichlorodiphenyltrichloroethane were primarily disseminated across the three modules since they were found in 100% and 97% of the analyzed soils, respectively. According to international regulations, none of the determined OCP concentrations are out of the limits. Additionally, the Cu, Zn, Fe, Pb, and Mn were found in all sampled soils from the three modules. The highest concentration of Fe was found in module II (1902.7 ± 332.2 mg kg-1), followed by Mn in module III (392.43 ± 74.43 mg kg-1), Zn in module I (38.36 ± 26.57 mg kg-1), Pb in module II (23.48 ± 6.48 mg kg-1), and Cu in module I (11.04 ± 3.83 mg kg-1) (p ≤ 0.05). These values did not exceed the limits proposed by international standards. The Cd was detected in most of the analyzed soils and all their values, with an average of 2 mg kg-1, surpassed the Mexican standards (0.35 mg kg-1). This study has mapped the main OCPs and heavy metals in the Juarez Valley and can serve as a starting point to further monitor the behave of xenobiotics. Since these recalcitrant compounds might be bio-accumulated in biological systems, further analytical methods, as well as remediation techniques, should be developed.

PLAGUICIDAS ORGANOCLORADOS EN AGUA DE LA LAGUNA NEGRA DE PUERTO MARQUÉS, ACAPULCO, GUERRERO, MÉXICO

The presence of organochlorine pesticides in aquatic systems is an issue of vital importance, because it affects non-renewable natural resources and as consequence the quality of water for organisms that live and use this resource. Coastal lagoons are aquatic systems that receive a large amount of organic matter and organic (petroleum hydrocarbons and pesticides) and inorganic (heavy metals) pollutants, where the biogeochemical and biological cycles of many species of commercial interest are carried out, as well as tourism activities. The objective of the present work was to quantify the concentrations of organochlorine pesticides in the water of the Laguna Negra of Puerto Marques, Acapulco. The organochlorine compounds were determined by gas chromatography analysis with electron capture detector ( 63 Ni). The results obtained in the sampling sites were divided into lagoon and discharge sites and did not show a significant difference, since the total average concentrations were 5.55 and 6.02 μg/L, respectively. It was also noted that during the dry season a total average of 6.80 μg/L was recorded, while in the rainy season it was 3.56 μg/L. According to the Official Mexican Standard NOM-SSA1-1994 there should be no organochlorine pesticides. Although concentrations are low (μg/L), they can cause some alteration to organisms through bioaccumulation and biomagnification with risks to the health of the natural system and the human being.

An integrated approach in subtropical agro-ecosystems: Active biomonitoring, environmental contaminants, bioaccumulation, and multiple biomarkers in fish

Aquatic contamination in agricultural areas is a global problem, characterized by a complex mixture of organic and inorganic pollutants whose effects on biota are unpredictable and poorly investigated. In this context, in the present study, the Neotropical fish Prochilodus lineatus was confined in situ for 120 days in two sites with different levels of anthropic impact: 1) a fish hatchery station, within the State University of Londrina (reference site - REF) and 2) an agro-ecosystem area in one of the most productive regions of southern Brazil (experimental site - EXP). We evaluated multiple biomarkers at different levels of biological organization, such as biotransformation and antioxidant enzymes, oxidative damages, DNA damages and liver histopathology. We also evaluated the occurrence of 22 organochlorine pesticides (OCPs) and 6 trace metals in water and sediment; and 33 current-use pesticides (CUPs) in the water; besides the presence of OCPs in the liver and metals in different tissues of the confined fish. The chemical analysis confirmed that the two environments presented different levels of contamination. We verified a distribution gradient of data in the principal component analysis (PCA), separating the REF fish to one side and the fish at the agricultural area (EXP) to the other side. In general, the biomarker responses were more altered in fish from the EXP than fish from the hatchery station; and this fish presented a greater accumulation of endosulfan (an increase of 18× compared to basal value) and showed oxidative, genetic, and histological damage. Through the Biomarkers Response Index (BRI), we found that the EXP fish demonstrated a decrease in health status compared with the REF fish during the confinement time, due to their exposure to a higher concentration of contaminants. In conclusion, the use of multiple biomarkers at different response levels is an important tool for environmental monitoring.

Validation of an Analytical Method for Simultaneous Determination of 18 Persistent Organic Pollutants in Trout Using LLE Extraction and GC-MS/MS.

Persistent organic pollutants, (POPs), are vast distributed compounds in environment which are recognized as one of the global pollution problems. These groups of materials being dangerous due to their high stability are accumulated in animal tissues and occurring in the food chain. One of the major paths through which persistent organic combinations access to human body is consuming polluted foods, particularly, fishes. Among aquatic animals, trout as one of the mostly consumed fishes in Tehran’s food basket was studied. In this study, two categories of persistent organic pollutants: Organochlorine pesticides (OCPs) including HCB, Dieldrin, Methoxychlor, α-, ϒ-Chlordane, α-, β-Endosulfan and o,p’-DDE, p,p’-DDE, o,p’-DDT, p,p’-DDT and the second group Polychlonitated biphenyls (PCBs) including seven PCB congeners which are called indicator PCBs (IUPAC nos.: 28,52,101,118,138,153 and 180) were determined in trout by GC-MS/MS in MRM monitoring mode and LLE extraction. The average recoveries of OCPs and PCBs at five concentration levels (1, 2, 5, 10 and 20 ng/g for PCBs and 5 times for OCPs) were in the range of 73-112%. The relative standard deviations of POPs in fish were in the range of 1.4-17.9% for all of the concentration levels. The limit of detections (LODs) and the limit of quantitations (LOQs) were between 0.6-8.3 and 2-25 µg/kg, respectively. The results indicated the presence of organochlorine pesticides in trout and the levels of p,p’-DDE and p,p’-DDT were within the range of < LOQ -12.83 and < LOQ -10.2 ng/g ww (wet weight), respectively. According to the results, OCPs residues were lower than maximum residue levels set by European Council Directives.

An Assessment of Water and Sediment Quality of River in India with Special Reference to Pesticide Contamination, a Case Study

Drinking water quality has become a serious issue in many countries due to the scarcity of fresh water resources. Water quality monitoring is the first step for the management and conservation of aquatic system. The contamination of OrganoChlorine Pesticides (OCPs) is very harmful for the environment and human beings. The presence of OCPs in surface water and in the bottom sediment in the Chalakudy River was investigated to evaluate the pollution load and distribution level of OCP seasonally over a period of 3 years from January 2013 to December 2015. Surface water sample and bottom sediment were collected from nine different sites (upstream, midstream and downstream) and analyzed for their profile of important physicochemical parameters and for persistence of OCP. To know the present trends in the river clearly ,temporal distribution and spatial distribution of OCPs and other parameters are studied based on three season(winter, summer, and monsoon).Obtained trend in each year were compared through sampling and analysis.

Evaluation of the use of dermal scutes and blood samples to determine organochlorine pesticides in Crocodylus moreletii: A non-destructive method for monitoring crocodiles and environmental health

This study determines the suitability of using blood plasma and dermal scute samples as a non-destructive technique for monitoring the health of Morelet’s crocodiles and the presence of organochlorine pesticides (OCPs) in the environment. We collected samples (blood plasma and caudal scutes) from 30 Morelet’s crocodiles (C. moreletii); 16 were wild, and 14 were captive. The 30 samples were analyzed for 24 different OCPs and compared in 10 groups based on chemical affinities (isomers and degradation products). Endrin and Chlordane were the most frequent OCP groups detected, found in 63% and 57% of the samples, respectively. We did not find significant differences in OCP concentrations in tissues (plasma and scutes) between wild and captive crocodiles; there were also no significant correlations among concentrations in tissues.Blood plasma and scutes are good indicators of OCP body burdens in Morelet’s crocodiles for monitoring the presence and fluctuation of toxicity in the environment; however, it is not possible to infer the concentrations in one tissue from the concentrations detected in the other tissue.Selecting which tissues to use for OCP analyses depends on the specific objectives of the researcher. For research, on individual health and local exposure to contaminants, plasma is suitable. For evaluating the presence over time of OCPs in the environment, the caudal dermal scutes are the most appropriate tissue. Overall, it is important to take into account the body condition to avoid biases due to bioamplification effects.

Fish consumption from urban impoundments: What are the health risks associated with DDTs and other organochlorine pesticides in fish to township residents of a major inland city

Organochlorine pesticides (OCPs) in South Africa have for the most part been banned, except dichlorodiphenyltrichloroethane (DDT) which is still used as malaria vector control. The aim of this study was to determine OCP residues in the aquatic fauna of one of South Africa's most populated areas, Soweto. Risk to human health through OCP exposure via fish consumption was investigated. Clarias gariepinus was chosen as bioindicator because it is an apex predator that is in abundance, but is also a valued food source. Dichlorodiphenyltrichloroethanes (DDTs), hexachlorocyclohexanes (HCHs), and chlordanes (CHLs) were detected in the fish tissue with the DDTs being the most prevalent at all sites. Of the three locations, Fleurhof, Orlando, and Lenasia, the latter location's fish had the highest ΣOCP load, ranging between 81 and 1190ng/gwm. The DDTs were determined to be from historic use, whereas the CHL levels indicated more recent inputs. Although the possibility of illegal use cannot be excluded completely, the presence of OCPs outside of their allowed areas of use indicate that these compounds not only stay in the aquatic systems long term, but may be of concern in areas previously not considered high risk areas. The OCP residues in C. gariepinus from the study area pose an extremely high risk to human health when consumed, and has a cancer risk as high as 1 in 10. This potential problem should be kept in consideration when developing national health and conservation strategies.

Residue behavior of organochlorine pesticides during the production process of yogurt and cheese

The presence of organochlorine pesticides (OCPs) in dairy products can lead to human exposure. This study investigated the behavior of OCP residues in milk during yogurt and cheese production. Gas chromatography with electron-capture detection (GC-ECD) was used to detect α-hexachlorocyclohexane (HCH), hexachlorobenzene (HCB), γ-HCH, g-chlordane, and α-chlordane in fresh milk, yogurt, and cheese. The results showed that fermentation reduced the residual concentration of OCPs in yogurt, with processing factors (PFs) ranging from 0.42 to 0.64. The reductions in residue levels during fermentation were due to the activity of the starter. The cheese making process increased the residual concentration of OCPs in cheese compared to raw milk, with PFs ranging from 2.37 to 4.93. Additionally, milk, yogurt, and cheese samples were purchased from local markets and OCP levels were analyzed. The target OCPs ranged from ND to 16.50 μg/kg in these samples.

Relationship between organochlorine pesticides and stress indicators in hawksbill sea turtle (Eretmochelys imbricata) nesting at Punta Xen (Campeche), Southern Gulf of Mexico.

Data on the impact of environmental pollution on the homeostasis of sea turtles remains scarce, particularly in the Southern Gulf of Mexico. As many municipalities along the coastline of the Yucatan Peninsula do not rely on a waste treatment plant, these organisms could be particularly vulnerable. We searched for relationships between the presence of organochlorine pesticides (OCP) and the level of several oxidative and pollutant stress indicators of the hawksbill sea turtle (Eretmochelys imbricata) during the 2010 nesting season at Punta Xen (Campeche, Mexico). Of the 30 sampled sea turtles, endosulfans, aldrin related (aldrin, endrin, dieldrin, endrin ketone, endrin aldehyde) and dichlorodiphenyldichloroethylene (DDT) families were detected in 17, 21 and 26, respectively. Significant correlation existed between the size of sea turtles with the concentration of methoxychlor, cholinesterase activity in plasma and heptachlors family, and catalase activity and hexachlorohexane family. Cholinesterase activity in washed erythrocytes and lipid peroxidation were positively correlated with glutathione reductase activity. Antioxidant enzyme actions seem adequate as no lipids damages were correlated with any OCPs. Future studies are necessary to evaluate the effect of OCPs on males of the area due to the significant detection of methoxychlor, which target endocrine functioning and increases its concentration with sea turtles size.

Presence of organochlorine pesticides in xoconostle (Opuntia joconostle) in the central region of Mexico

Mexico has many natural resources for use in the food industry. In recent years Xoconostle, which is considered as a traditional food, has gained importance due to key its components such as fiber, antioxidants, and fermentative bacteria found in both the peel and fruit, which could benefit human and animal health. Information on the presence of organic contaminants such as pesticides in Xoconostle is important in protecting its reputation as a healthy food. The objective of this research was to measure the concentration of pesticides in the peel of Xoconostle in four 50 m2 plots in the same production area. The samples were taken in the state of Hidalgo, which is one major region of production. Fruits were collected from upper and lower levels in five plots. Organochlorine pesticides in peel samples were extracted by Soxhlet extraction, purified with chromatographic columns, and finally analyzed by gas chromatography with electron capture detector (ECD). The results showed a predominance of heptachlor, HCH derivatives and DDT isomers but there is no permissible limit for these compounds in this fruit. The presence of organochlorines suggests the use of these compounds in control of pests in crops and livestock, in spite of the substitution of these compounds, principally by organophosphorus pesticides. Regulation is necessary to ensure the safety of the product for consumption and trade.

Organochlorine pesticide levels in maternal blood and placental tissue with reference to preterm birth: a recent trend in North Indian population.

Organochlorine pesticides (OCPs) have been widely used in public health and agriculture programs in developed as well as developing countries, including India. Being xenoestrogenic in nature, OCPs may act as endocrine disruptors leading to preterm birth (PTB) through disturbance of normal estrogen-progesterone ratio. PTB is the leading cause of neonatal deaths worldwide. Therefore, the present study is aimed to determine the extent to which persistent environmental chemicals may accumulate in pregnant women and placenta and ascertain possible associations between exposure level and period of gestation (POG), baby weight, and/or placental weight in PTB cases. Maternal blood and placenta samples of PTB cases (n = 50) and subjects of term delivery as controls (n = 50) were collected. OCP residue levels were estimated by the gas chromatography system equipped with an electron capture detector. Significantly higher levels of α-hexachlorocyclohexane (α-HCH), β-hexachlorocyclohexane (β-HCH), dichlorodiphenyldichloroethane (DDD), and dichlorodiphenyldichloroethylene (DDE) were found in maternal blood of PTB cases as compared to control. Significantly higher levels of DDE and dichlorodiphenyltrichloroethane (DDT) were also found in placental tissue of PTB cases as compared to control group. There was a statistically significant negative correlation between maternal blood level of α-HCH and birth-weight (r = -0.299) and POG (r = -0.234). γ-Hexachlorocyclohexane (γ-HCH) and dieldrin had a negative correlation with placental weight (r = -0.401 and -0.256, respectively), and DDE and β-HCH had a negative correlation with POG (r = -0.251 and -0.229, respectively). The presence of OCPs in maternal blood and placental tissue represents prenatal exposure hazard for fetuses due to chronic bioaccumulation and poor elimination with possible deleterious effect on health.

The sediment load and deposition by river discharge and their relation to organochlorine pesticides pollutants in the sediment bottom of Nha Trang Bay, Vietnam

Based on previous results from the “River reef impact studies project that was carried out as a co-operation programme between ZMT (Germany) and NIO (Vietnam) from 2008–2012, the variation of sediment load and associated persistent organic pollutants were investigated in Nha Trang Bay. In northern parts of the bay, both suspended matter load and deposition rates are high during the rainy season (flood events). The total suspended matter (TSM) and particulate nitrogen (PN) concentration show variations both with season (dry and rainy seasons) and increasing distances from the coast: TSM ranged from 2.30 to 19.79 mgL-1; and PN concentration ranged from 0.006 to 0.055 mgL-1. High deposition rates occurred both near the shore and in mid-bay, ranging from 12.8 to 36.1 g m-2 d-1. In the southern section of the bay, sediment deposition was slightly lower, with little seasonal variation. The highest deposition rate was measured at the river estuarine site, amounting to 9.1 g m-2 d-1 (dry season) and 9.0 g m-2 d-1 (rainy season). Further, persistent organic pollutants (POP) concentrations in sediment samples and sediment cores clearly showed the presence of organo-chlorine pesticides (OCP pollutant). High accumulation levels of OCP components were found in almost all sediment samples of Nha Trang Bay. The DDT concentrations showed high levels in sediment located in the estuary at the northern part of the bay (ranged: 20.11µg kg-1 to 5.28µg kg-1), and in the southern part (B1) 3.76µg kg-1. This study provides essential data and information, which are needed to assess the long-term impacts of river input on the degradation of marine ecosystems in the coastal waters of Nha Trang Bay.

A simple Streptomyces spore-based impedimetric biosensor to detect lindane pesticide

Lindane is a pesticide potentially harmful to environment and human health and in general, its detection involves mostly tedious, expensive and time-consuming techniques. A new strategy to detect lindane can be focused on the activity of Streptomyces strain M7 (SM7), which is capable to grow in the presence of organochlorine pesticides (OCPs) as carbon source. On this regard, the aim of this work is to present an optimized design of a microbial biosensor prototype based on a SM7 spore platform to detect and quantify lindane by electrochemical impedance spectroscopy (EIS) as the transduction method. By means of this technique, the metabolic bacterial activity was evaluated by analyzing a set of electrical parameters calculated by fitting the measured impedance spectra through an equivalent electrical circuit. Activity studies were performed by incubating the SM7 spore platform with (optimized incubation conditions) and without (to be used in a practical biosensor) shaking in the presence of lindane. In all cases, bacterial activity was measured by the impedance changes produced in the cells due to lindane removal from the culture medium. This proposed label-free impedimetric biosensor is simple, cost-effective and feasible to detect changes in the lindane concentration as low as 120μgL−1 in less than 2 days without sample pretreatment. In addition, the surface of electrodes can be reused for several different tests. This sensor prototype represents a valuable alternative for OCPs detection.

Determination of organochlorine pesticide concentrations in flathead mullet (Mugil cephalus) caught from the western Black Sea coast of Turkey.

The objective of this study was to determine the levels of 14 organochlorine pesticides (OCPs) in flathead mullet (Mugil cephalus) caught from the western Black Sea coast of Turkey. The fish samples were caught from five different locations of the western Black Sea coast of Turkey in August 2009. Organochlorine pesticides were extracted from the liver tissues, and then the levels of OCPs were measured using gas chromatography with an electron capture detector. Organochlorine pesticides were detected in all locations. The levels of total OCPs in fish samples ranged between 0.224 and 1.103μgg(-1) dry weight in the western Black Sea coast of Turkey. DDT, beta-HCH, and endosulfan I were the dominant OCPs in the fish samples. The levels of DDT in fish samples ranged between 0.081 and 0.186μgg(-1) dry weight. The levels of total HCH in fish samples ranged between 0.007 and 0.376μgg(-1) dry weight in the western Black Sea coast of Turkey. Although the usage of OCPs was banned in Turkey, the results of this study clearly indicated the presence of OCPs in the western Black Sea coast of Turkey and exposure of living organisms to these chemicals.