Organochlorine insecticide residues are found in surface, irrigated water samples from several districts in Bangladesh

Uncertainty of pesticides in foodstuffs, associated environmental and health risks to humans-a critical case of Bangladesh with respect to global food policy

The uncertain fate and transport pathways of applied pesticides are the key hidden threats with respect to the safety and quality evaluation of foodstuffs in Bangladesh. The risk assessment of and uncertainty about applied pesticides are poorly explored due to weak regulatory systems, farmer ignorance, intensive agricultural practices, and lack of available research data on improper handling of pesticides on farming lands with poor phytosanitary management. However, increasing evidence suggests that the prevalence of pesticides in common foodstuffs is due to their uptake by crops and improper management of crop protection practices. Besides, the biotransformation of pesticides in common Bangladeshi food products is poorly understood. Several studies have reported higher concentrations of pesticides than allowed by European Union guidelines in Bangladeshi foodstuffs. However, to date, no systematic review with critical discussion on current research findings and knowledge gaps concerning fate, uncertainty, and health risks of pesticides in the foodstuffs of Bangladesh is published. Therefore, this review summarizes the findings of existing literature on pesticide residue in foodstuffs and points out the weaknesses in the regulatory system and risk assessments for highlighting the critical challenges to food safety in Bangladesh as compared to global food policy. In addition, strategies for the sustainable management of residual pesticides are also discussed.

Water pollution in Bangladesh and its impact on public health

Bangladesh – one of the most densely populated countries of the world— has plentiful water sources, but these sources are being polluted continuously. Both surface water and groundwater sources are contaminated with different contaminants like toxic trace metals, coliforms as well as other organic and inorganic pollutants. As most of the population uses these water sources, especially groundwater sources which contain an elevated amount of arsenic throughout the country; health risk regarding consuming water is very high. Death due to water-borne diseases is widespread in Bangladesh, particularly among children. Anthropogenic sources such as untreated industrial effluents, improper disposal of domestic waste, agricultural runoffs are the main contributors regarding water pollution. A total water pollution status of this country, as well as the sources of this severe condition, is crucial to evaluate public health risk. For this purpose, we reviewed hundreds of well recognized international and national journals, conference proceedings and other related documents to draw a complete picture of recent water pollution status and its impact on public health; also the sources of water pollution are identified.

GC-MS/MS determination and ecological risk assessment of pesticides in aquatic system: A case study in Hooghly River basin in West Bengal, India

A liquid-liquid extraction (LLE) for water and modified QuEChERS (quick, easy, cheap, effective, rugged, and safe) method for sediment combined with gas chromatography-tandem mass spectrometry (GC-MS/MS) detection in multiple reaction monitoring (MRM) mode was standardized for determination of 31 pesticides. Performance characteristics for the selected pesticides were acceptable according to European Commission's (EC) guidelines for method validation (recovery 70-120%, RSD <20% and R² value ≥ 0.99). River, pond and tubewell water and river sediment samples (64 nos.) were collected from Hooghly River basin in West Bengal, India during 2014-2016. About 42% of the samples showed the presence of 19 pesticides with the highest loading of total pesticides (T-pesticides) in river water (3.01 ng mL^-1) followed by sediment (1.25 ng g^-1), pond (0.40 ng mL^-1) and tubewell (0.02 ng mL^-1) water. The non-agricultural OC (organochlorine) insecticides were detected in all river water and sediment samples mainly due to HCHs (hexachlorocyclohexane) from old source and fresh use of DDTs (dichlorodiphenyltrichloroethane) in local areas. No OC insecticides were detected in pond and tubewell water. Maximum residues of some recommended pesticides in agriculture were obtained in pond water. Most of the river water samples (93.7%) were in excess of EC limit (0.50 ng mL^-1) of T-pesticides for drinking followed by pond water samples (56.2%). Tubewell water samples were free from T-pesticide threat but exceeded the EC limit (0.10 ng mL^-1) for single pesticide in case of chlorpyrifos only. Ecological risk on aquatic animals was observed for OCs in river and chlorpyrifos in pond aquatic ecosystem.

Levels and Distribution of Pollutants in the Waters of an Aquatic Ecosystem in Northern Mexico

The availability of good quality water resources is essential to ensure healthy crops and livestock. The objective of this study was to evaluate the level of pollution in Bustillos Lagoon in northern Mexico. Physical-chemical parameters like sodium, chloride, sulfate, electrical conductivity, nitrates, and the pesticide dichlorodiphenyltrichloroethane (DDT) were analyzed to determine the water quality available in the lagoon. Although DDT has been banned in several countries, it is still used for agricultural purposes in Mexico and its presence in this area had not been analyzed previously. Bustillos Lagoon was divided into three zones for the evaluation: (1) industrial; (2) communal lands; and (3) agricultural. The highest concentrations of sodium (2360 mg/L) and SAR (41 meq/L) reported in the industrial zone are values exceeding the United Nations Food and Agricultural Organization (FAO) irrigation water quality guidelines. DDT and its metabolites were detected in all of the 21 sites analyzed, in the agricultural zone ∑DDTs = 2804 ng/mL, this level is much higher than those reported for other water bodies in Mexico and around the world where DDT has been used heavily. The water in the communal zone is the least contaminated, but can only be recommended for irrigation of plants with high stress tolerance and not for crops.

A comprehensive assessment of arsenic in commonly consumed foodstuffs to evaluate the potential health risk in Bangladesh

Arsenic (As), particularly of its inorganic form (iAs) is highly toxic, and its presence in food composites is a matter of concern for the public health safety, specifically in Bangladesh which is regarded as the most arsenic affected country throughout the world. This study was carried out to investigate the levels of As in the composite samples of commonly consumed foodstuffs collected from 30 different agro-ecological zones for the first time in Bangladesh. Most of the individual food composites contain a considerable amount of As which was, as a whole, in the range of 0.077-1.5mg/kg fw which was lower than those reported from Spain, EU, France, Korea, whereas higher than those of Mexico, Chile, Japan, Cambodia, Hong Kong, Serbia, respectively. Cereals, vegetables, milk, and fish contribute about 90% to the daily intake of inorganic arsenic. Human health risk of dietary iAs was assessed separately for both the rural and urban adults. The estimated daily dietary intakes (EDI) of iAs for the exposed rural (3.5) and urban residents (3.2 μg/kg-BW/day) clearly exceeded the previous provisional tolerable daily intake (PTDI) value of 2.1 μg/kg-BW/day, recommended by the World Health Organization (WHO). From the health point of view, this study concluded that both the rural and urban residents of Bangladesh are exposed to carcinogenic and non-carcinogenic risks who consume As-contaminated water and foodstuffs.

New priority substances of the European Water Framework Directive: biocides, pesticides and brominated flame retardants in the aquatic environment of Denmark

The biocides cybutryn (Irgarol) and terbutryn, the herbicides aclonifen and bifenox, the insecticides cypermethrin and heptachlor/heptachlor epoxide and the brominated flame retardant hexabromocyclododecane (HBCD) are new priority substances of the Water Framework Directive of the European Union. In order to gain knowledge about their presence in the aquatic environment in an off-season situation with regard to pesticide and biocide applications, these substances were analysed in freshwater, seawater and fish samples from Denmark. Aclonifen, bifenox, cypermethrin and heptachlor were below the limits of detection (LODs) in all samples. However, the LODs for cypermethrin and heptachlor exceeded the annual average environmental quality standards (AA-EQSs). Cybutryn, terbutryn, heptachlor epoxide and HBCD were detected in the majority of samples, with detection frequencies of 100% for heptachlor epoxide and HBCD in water and 90% in fish. No concentration was above maximum allowable concentration (MAC)-EQS values, but AA-EQS values were exceeded for all four compounds by several samples, including 100% of the water samples with regard to heptachlor epoxide. Methodological issues remain for cypermethrin, and to a certain extent for heptachlor/heptachlor epoxide, for which water LODs were above AA-EQSs although a water volume of 12L was combined with very sensitive high resolution mass spectrometry.

Residues of legacy organochlorine contaminants in the milk of Alpine and Saanen goats from the central region of Mexico

This study investigated a suite of legacy organochlorine contaminants in the milk of two breeds of goats raised in the central region of Mexico, where this agricultural production is of national (Mexican) economic importance. Forty milk samples from Alpine and Saanen goats were assessed. It was found that the concentrations of the majority of organochlorine pesticides in milk samples were lower than those stipulated in Mexican and international regulation. The values in both breeds of goat exceeded the upper permissible limits of Codex Alimentarius for delta hexachloro cyclohexane (HCH) (17.3 of samples of Saanen) and heptachlor plus heptachlor epoxide (50 % and 13 % of samples). It may be concluded that milk from these goat breeds from central Mexico showed some risks of contamination in certain times of the year (dry season). However, under further assessment and use of pesticides the goat's milk will likely be safe for human consumption and for use in products such as cheeses, regional candies and desserts (cajeta). In recent years, goat milk production has increased in the central regions and it is an economic alternative to milk from livestock. It is necessary to continue the monitoring of goat's milk to assess the presence and control of HCHs through best management practices.