Organochlorine pesticide residues in inland wetland fishes of Karnataka, India and their implications on human dietary intake

Strategies for mitigation of pesticides from the environment through alternative approaches: A review of recent developments and future prospects

Chemical-based peticides are having negative impacts on both the healths of human beings and plants as well. The World Health Organisation (WHO), reported that each year, >25 million individuals in poor nations are having acute pesticide poisoning cases along with 20,000 fatal injuries at global level. Normally, only ∼0.1% of the pesticide reaches to the intended targets, and rest amount is expected to come into the food chain/environment for a longer period of time. Therefore, it is crucial to reduce the amounts of pesticides present in the soil. Physical or chemical treatments are either expensive or incapable to do so. Hence, pesticide detoxification can be achieved through bioremediation/biotechnologies, including nano-based methodologies, integrated approaches etc. These are relatively affordable, efficient and environmentally sound methods. Therefore, alternate strategies like as advanced biotechnological tools like as CRISPR Cas system, RNAi and genetic engineering for development of insects and pest resistant plants which are directly involved in the development of disease- and pest-resistant plants and indirectly reduce the use of pesticides. Omics tools and multi omics approaches like metagenomics, genomics, transcriptomics, proteomics, and metabolomics for the efficient functional gene mining and their validation for bioremediation of pesticides also discussed from the literatures. Overall, the review focuses on the most recent advancements in bioremediation methods to lessen the effects of pesticides along with the role of microorganisms in pesticides elimination. Further, pesticide detection is also a big challenge which can be done by using HPLC, GC, SERS, and LSPR ELISA etc. which have also been described in this review.

Wetland health assessment using DPSI framework: a case study in Kolkata Metropolitan Area

Wetlands are among the most valuable components of the ecosystem, playing an important role in preventing floods, maintaining the hydrological cycle, protecting against natural hazards, and controlling local weather conditions and ecological restoration. The Kolkata Metropolitan Area (KMA) is considered one of the most ecologically valuable regions in terms of wetland ecosystem, but due to haphazard development and human activities, the wetlands of the city are under constant threat of degradation. Therefore, this study aims to assess the factors responsible for wetland health and their dynamics using Driving Force-Pressure-State-Impact (DPSI) framework. To assess wetland health during 2011-2020, seventeen indicators and four sub-indicators were selected to calculate weights using the analytic hierarchy process (AHP). The results showed that most of the municipalities in the healthy category were in the pressure (P) section in 2011, while fluctuations were observed in the impact (I) section in several wards during 2011-20. The condition section (S) showed the overall change in the water, vegetation, and built-up categories from 2011 to 2020, so the most dominant category was "healthy," followed by "unhealthy" and "poor." The highly significant factors worsening wetland health were population density (B1), road density (B3), per capita wastewater generation (B5), per capita solid waste generation (B7), biological oxygen demand (D1a), dissolved oxygen (D1b), pH (D1c), and total coliform (D1d). The results of the study can help develop sustainable conservation and management of the wetland ecosystem in the KMA urban area and at the global level with similar geographical conditions.

Exploring vulnerabilities of inland fisheries in Indian context with special reference to climate change and their mitigation and adaptation: a review

Tropical inland capture fisheries are susceptible to a series of vulnerabilities such as habitat destruction, biodiversity loss, pollution, overfishing, invasive species and anthropogenic climate change. A comprehensive review of the impact of climatic uncertainties on Indian inland fisheries has not been adequately attempted yet. Recent approaches emphasizing ecosystem-based management in a regional context, specific to inland fisheries for combating climatic changes, have not been reported to date. The paper presents a critical bibliometric review of the climatic vulnerabilities faced by Indian inland fishery resources and various adaptive and mitigation strategies put forward by the country for the sustainability of the resources. In this communication, a systematic review of the impact of climate change and other stressors on various inland ecosystems of the subcontinent and the ecosystem-based management strategies adopted in India is presented and discussed.

Level of pesticides contamination in the major river systems: A review on South Asian countries perspective

Pesticides are chemical compounds used worldwide for different purposes. These chemicals are well known for their long life, high toxicity, and slow degradation process. Many developed countries including South Asian countries banned the use of pesticides for their adverse effects. However, several pesticides are found incessantly in water and soil. To highlight the recent situation of pesticide contamination in South Asian river systems, we have studied 136 relevant articles published from 2015 to 2020. Articles were gathered using several commonly available search engines and organized according to information related to river systems of South Asian countries. After thoroughly examining those research articles, we summarized that most of the river systems are contaminated by pesticides, where DDTs, HCHs, endosulfan, heptachlor, and chlorpyrifos are the key recognized compounds among them. Comparing the level of pesticides with standard guidelines, we found that the Tapi River and Chilika Lake of India are considerably more contaminated than other river basins. Multivariate analyses identified the industrial discharge and agricultural run-off of chemicals as the probable sources of pesticides in these rivers. By analyzing the amount of annual pesticide production, their use, and accordingly their considerable presence in the water systems of the South Asian countries, it is evident that the banned pesticides are used regularly by these countries and thus contaminating the environment. Therefore, the formulations of appropriate rules and their enforcement to control the manufacture and solicitation of such pesticides are an urgent need to save the environment.

Levels and distribution pattern of organochlorine pesticide residues in eggs of 22 terrestrial birds from Tamil Nadu, India

Long-term monitoring is essential to assess the patterns and distribution of the residues of organochlorine pesticides (OCPs) in biota. Bird eggs have several advantages than other environmental matrixes, which have been used extensively to portray the accumulation and distribution of OCPs. The present study investigated the organochlorine pesticide (OCP) residues in eggs of 22 species of terrestrial birds collected from Tamil Nadu, India. Eggs found abandoned were collected during nest monitoring between 2001 and 2008 and analyzed for the presence of organochlorine pesticide residues. The results showed that the mean concentrations of total hexachlorohexane (∑HCHs), total dichlorodiphenyltrichloroethane (∑DDTs), heptachlor epoxide, and dieldrin ranged from non-detectable (nd) to 2800 ng/g, nd to1000 ng/g, nd to 700 ng/g, and nd to 240 ng/g on a wet mass (wm) basis, respectively. The variation in magnitude of contamination among the species and feeding guilds were not significantly different (p > 0.05). Among the OCPs analyzed, the residues of β-HCH and p,p'-DDE were found to be the abundant in concentration. Similarly, among various bird species studied, the highest concentrations of ∑OCPs (> 5000 ng/g wm) were recorded in the eggs of gray junglefowl, scaly-breasted munia, and red-whiskered bulbul. This may be due to their widespread occurrence of their habitat at proximity to the agricultural fields, where organochlorines were in use until recently. Among the various contaminants analyzed, concentrations of p,p'-DDE and heptachlor epoxide exceeded the threshold levels of toxicity for wild birds in > 5% of the egg samples. Hence, this study indicates the need for continued monitoring and further systematic ecotoxicological investigation of these compounds not only in eggs but also in other environmental media.

Organochlorine Pesticide Residues Among Colonial Nesting Birds in Tamil Nadu, India: A Maiden Assessment from Their Breeding Grounds

Use of pesticides continues to be indiscriminate, and birds are one of the worst affected non-targeted organisms. Information on the ill effects of pesticides on birds far from desired in India. Despite the presence of a wide variety and number of birds, there is exceedingly little data on organochlorine pesticide (OCP) residues in colonial nesting birds in sanctuaries of India. A total of 76 individuals belonging to 14 species of birds found dead between March 2008 and March 2010 were analyzed for pesticide residues in various tissues. Of all the OCPs analyzed, concentration of HCH was found to be the highest. Magnitude of contamination varied widely among species. Accumulation pattern of OCPs in colonial nesting birds was in the order ∑HCH > ∑endosulfan > ∑DDT > heptachlor epoxide > dieldrin. Pesticides, namely p,p-DDE and β-HCH contributed most towards the total OCPs. Concentrations of DDT and its metabolites, HCH and isomers, dieldrin, and heptachlor epoxide were lower than the concentrations reported for various species of birds elsewhere in India. Although the sanctuaries presently studied have official boundaries, physical demarcations are missing and there are no proper earthen dykes particularly in Vedanthangal and Koonthankulam Bird Sanctuaries. During monsoon, runoff not only floods the Sanctuaries but also the cultivated areas nearby. Run off brings in residues of pesticides and fertilizers from the agricultural lands into the sanctuaries. Although OCP results in this study were below threshold limits, it may be noted that the long duration exposure even to low levels of pesticides could create a significant impact at population level. Hence, earthen dykes need to be built to avoid agricultural runoff entering the Sanctuary and also help to hold sufficient amount of water for breeding birds.

Status of pesticide residues in water, sediment, and fishes of Chilika Lake, India

Chilika Lake is the largest coastal lagoon in Asia and the second largest in the world covering an area of 1100 km² and spread over three districts of Odisha state of India. It is the first Indian wetland designated as a wetland of international importance under the Ramsar Convention in 1981. The lake ecosystem sustains large and diversified resources of plants and animals including fisheries. Pollution of the ecosystem caused by residues of pesticides originating from different sources was assessed through multiple sampling from 2012 to 2016 from three potential sites of contamination, viz., Palur Bridge, Daya River Estuary, and Makara River. Incidence of organochlorinated (OC) pesticide residues was noticed in about 25% water samples. HCH (α, γ&δ), DDD (op^|), DDE (op^|&pp.^|) and heptachlor were the OCs detected in concentration varying from 0.025 to 23.4 μg/l. None of the eight targeted synthetic pyrethroid (SP) pesticides was found in water, but among the organophosphates (OP), chlorpyrifos (0.019-2.73 μg/l), and dichlorvos (0.647 μg/l) were recorded. In sediment samples, residues of OC or OP pesticides were not present, but one SP pesticide was recorded. Fish samples were contaminated to the extent of 55%, mostly with residues of OCs and OPs and less with SPs. However, their concentrations were below the permissible limit, so there was no direct threat of health hazards to humans.

Potentially Heterogeneous Cross-Sectional Associations of Seafood Consumption with Diabetes and Glycemia in Urban South Asia

Aims: In this study, we aimed to estimate cross-sectional associations of fish or shellfish consumption with diabetes and glycemia in three South Asian mega-cities. Methods: We analyzed baseline data from 2010-2011 of a cohort (n = 16,287) representing the population ≥20 years old that was neither pregnant nor on bedrest from Karachi (unweighted n = 4017), Delhi (unweighted n = 5364), and Chennai (unweighted n = 6906). Diabetes was defined as self-reported physician-diagnosed diabetes, fasting plasma glucose ≥126 mg/dL (7.0 mmol/L), or glycated hemoglobin A1c (HbA1c) ≥6.5% (48 mmol/mol). We estimated adjusted and unadjusted odds ratios for diabetes using survey estimation logistic regression for each city, and differences in glucose and HbA1c using survey estimation linear regression for each city. Adjusted models controlled for age, gender, body mass index, waist-height ratio, sedentary lifestyle, educational attainment, tobacco use, an unhealthy diet index score, income, self-reported physician diagnosis of high blood pressure, and self-reported physician diagnosis of high cholesterol. Results: The prevalence of diabetes was 26.7% (95% confidence interval: 24.8, 28.6) in Chennai, 36.7% (32.9, 40.5) in Delhi, and 24.3% (22.0, 26.6) in Karachi. Fish and shellfish were consumed more frequently in Chennai than in the other two cities. In Chennai, the adjusted odds ratio for diabetes, comparing more than weekly vs. less than weekly fish consumption, was 0.81 (0.61, 1.08); in Delhi, it was 1.18 (0.87, 1.58), and, in Karachi, it was 1.30 (0.94, 1.80). In Chennai, the adjusted odds ratio of prevalent diabetes among persons consuming shellfish more than weekly versus less than weekly was 1.08 (95% CI: 0.90, 1.30); in Delhi, it was 1.35 (0.90, 2.01), and, in Karachi, it was 1.68 (0.98, 2.86). Conclusions: Both the direction and the magnitude of association between seafood consumption and glycemia may vary by city. Further investigation into specific locally consumed seafoods and their prospective associations with incident diabetes and related pathophysiology are warranted.

Levels of organochlorine pesticide residues in fresh water fishes of three bird sanctuaries in Tamil Nadu, India

Organochlorine pesticide (OCP) residues were determined in nine species of fresh water fishes caught from three bird sanctuaries in Tamil Nadu, India. A total of 302 fishes were analyzed for various types of OCPS. OCPs, namely hexachlorocyclohexane (HCH), dichloro diphenyl trichloroethane (DDT), heptachlor epoxide, endosulfan, and dieldrin were detected among various species of fishes. Among the various OCPs analyzed, HCH was the most frequently detected pesticides. Among the HCH isomers, β HCH contributed more than 50% to the Σ HCH. p,p' DDT, the metabolites of DDT, had high percentage of occurrence. Among the cyclodiene insecticide residues, endosulfan was detected in more than 60% of the fishes. Varying levels of ΣOCPs (a sum of Σ HCH, Σ DDT, Σ endosulfan, heptachlor epoxide, and dieldrin) were detected in various fish species, although it was not significant (p > 0.05). However, significant variations in OCPs were observed among location and between seasons (p < 0.05). However, continuous monitoring is recommended to facilitate the early identification of risks not only to the fishes, but also to fish-eating birds breeding in these sanctuaries.

Environment and human exposure to persistent organic pollutants (POPs) in India: a systematic review of recent and historical data

Persistent organic pollutants (POPs) have been used in a wide range of agricultural and industrial commodities, resulting in vigorous deterioration of environment and human health. A number of studies on the occurrence of POPs confirm their presence in various environmental compartments and human body. In order to deal with this global concern, India has recently prepared the National Implementation Plan (NIP) of the Stockholm Convention. Common beliefs point at India as a hot spot of POP contamination and human exposure; however no systematic analysis was ever performed so far considering all available past data on POP occurrence. This review aims to examine the distribution pattern of POPs in multicompartment environment and human samples, meta-analysis of time trends in exposure levels to environment and humans, and cross country comparison of POP contamination with China. Based on this review, it can be concluded that the Indian environment and human population are highly contaminated by DDTs and HCHs; however scarcity of data on other POPs makes it challenging to assess their nationwide human and environmental exposure. No evidence of a general decline in DDT and HCH residues in the environment and human body come out from the meta-analysis of time trend. While comparing contamination levels between India and China, tendency towards decline in POP contamination is visible in China, unlike India.

Accumulation pattern of persistent organochlorine pesticides in liver tissues of various species of birds from India

As part of a large study on assessing the impact of environmental contaminants in Indian avifauna, the presence of organochlorine pesticides (OCPs) in liver tissues of 16 species of birds collected from Ahmedabad, India during 2005-2007 was quantified. The higher concentrations of total organochlorine pesticides were detected in livers of shikra Accipiter badius (3.43 ± 0.99 μg/g wet wt) and the lower levels in white ibis Pseudibis papillosa (0.02 ± 0.01 μg/g wet wt). Marked differences in the concentrations of total OCPs occurred among species (p < 0.05). Concentrations of DDT and its metabolites, hexachlorocyclohexane (HCH) and isomers, dieldrin, and heptachlor epoxide were lower than the concentrations reported for various species of birds in India. Accumulation pattern of organochlorine pesticides in birds was, in general, in the order HCH > DDT > heptachlor epoxide > dieldrin. Among various pesticides analyzed, p,p'-DDE and β-HCH contributed maximum towards the total OCPs and study indicates the continuous use of lindane and DDT for agriculture and public health purpose, respectively. Although no serious threat is posed by any of the organochlorine pesticides detected in the present study species, continued monitoring is recommended.