Interventions to reduce pesticide exposure from the agricultural sector in Africa: a workshop report

Despite the fact that several cases of unsafe pesticide use among farmers in different parts of Africa have been documented, there is limited evidence regarding which specific interventions are effective in reducing pesticide exposure and associated risks to human health and ecology. The overall goal of the African Pesticide Intervention Project (APsent) study is to better understand ongoing research and public health activities related to interventions in Africa through the implementation of suitable target-specific situations or use contexts. A systematic review of the scientific literature on pesticide intervention studies with a focus on Africa was conducted. This was followed by a qualitative survey among stakeholders involved in pesticide research or management in the African region to learn about barriers to and promoters of successful interventions. The project was concluded with an international workshop in November 2021, where a broad range of topics relevant to occupational and environmental health risks were discussed such as acute poisoning, street pesticides, switching to alternatives, or disposal of empty pesticide containers. Key areas of improvement identified were training on pesticide usage techniques, research on the effectiveness of interventions targeted at exposure reduction and/or behavioral changes, awareness raising, implementation of adequate policies, and enforcement of regulations and processes

Levels of Polycyclic Aromatic Hydrocarbons, Polychlorinated Biphenyls, and Organochlorine Pesticides in Various Tissues of White-Backed Vulture in India

This study provides information on the current status of contamination by polycyclic aromatic hydrocarbons (PAHs), polychlorinated biphenyls (PCBs), and organochlorine pesticides (OCPs) in the tissues of endangered White-backed Vulture Gyps bengalensis in India. Chemical analyses revealed detectable amounts of PAHs, PCBs, and OCPs. Concentration ranges of ∑PAHs, ∑PCBs, and ∑OCPs in tissues were 60–2037 ng/g, 30–5790 ng/g, and 3.2–5836 ng/g wet weight, respectively. 1,1-Dichloro-2,2-bis(p-chlorophenyl)ethylene (p,p′-DDE) concentrations ranged from below detectable level to 599 ng/g wet weight, representing more than 90% of the total dichlorodiphenyltrichloroethane (DDT). Among the various OCPs analyzed, p,p′-DDE was detected most frequently. All the contaminants recorded show higher accumulation in liver than other tissues. Levels of contaminants measured in the tissues of vulture are comparable with the levels documented in a number of avian species and are lower than those reported to have caused deleterious effects. Although no threat is expected from the current level of contamination, the presence of varying levels of contaminants and their additive or synergistic toxicity is a cause of concern to vultures. Values reported in this study can serve as guideline for future research

Polycyclic Aromatic Hydrocarbons in Various Species of Fishes from Mumbai Harbour, India, and Their Dietary Intake Concentration to Human

Polycyclic aromatic hydrocarbons (PAHs) are ubiquitous environmental contaminants which have caused worldwide concerns as toxic pollutant. This study reports the concentrations of 15 PAHs in 5 species of fish samples collected along the harbour line, Mumbai, between 2006 and 2008. Among 5 species of fish investigated, Mandeli, Coilia dussimieri, detected the maximum concentration of PAHs (P<0.05) followed by Doma, Otolithes ruber. The concentration of total and carcinogenic PAHs ranged from 17.43 to 70.44 ng/g wet wt. and 9.49 to 31.23 ng/g wet wt, respectively, among the species tested. The lower-molecular-weight PAHs were detected at highest levels. Estimated intakes of PAHs by fish consumption for the general population were ranged between 1.77 and 10.70 ng/kg body weight/day. Mandeli contributed to the highest intakes of PAHs. The toxic equivalents (TEQs) of PAHs were calculated using a TEQ proposed in literature, and the intake ranged from 8.39 to 15.78 pg TEQ/kg body weight/d. The estimated excess cancer risk value (2.37×10−7–1.43×10−6) from fish consumption for the general population exceeded the guideline value (1.0 × 10−6) for potential cancer risk

Antifilarial drugs, in the doses employed in mass drug administrations by the Global Programme to Eliminate Lymphatic Filariasis, reverse lymphatic pathology in children with Brugia malayi infection

Lymphatic filariasis is increasingly viewed as the result of an infection that is often acquired in childhood. The lymphatic pathology that occurs in the disease is generally believed to be irreversible. In a recent study in India, Doppler ultrasonography and lymphoscintigraphy were used to explore subclinical pathology in 100 children from an area endemic for Brugia malayi infection. All the children investigated showed some evidence of current or previous filarial infection. Some were microfilaraemic but asymptomatic, some were amicrofilaraemic but had filarial disease or a past history of microfilaraemia and/or filarial disease, and the rest, though amicrofilaraemic, asymptomatic and without any history of microfilaraemia or filarial disease, were seropositive for antifilarial IgG4 antibodies. All the children were treated every 6 months, with a single combined dose of diethylcarbamazine (6 mg/kg) and albendazole (400 mg), and followed up for 24 months. By the end of this period all but one of the children were amicrofilaraemic and the ‘filarial dance sign’ could not be detected in any of the 14 children who had initially been found positive for this sign. Although lymphoscintigraphy revealed lymph-node and lymph-vessel damage in 82% of the children at enrolment, in about 67% of the children this pathology was markedly reduced by the 24-month follow-up. These results indicate that the drug regimens used in the mass drug administrations run by the Global Programme to Eliminate Lymphatic Filariasis are capable of reversing subclinical lymphatic damage and can provide benefits other than interruption of transmission in endemic areas. The implications of these findings are presented and discussed

Recovery of elemental sulphur and copper values from chalcopyrite concentrates by direct leaching in ferric chloride solution

The influence of different variables on the recovery of copper and sulphur from chalcopyrite concentrates by direct leaching in ferric chloride solution has been studied. It is found that the finer the grind of the concentrate and the higher the strength of ferric chloride in the solution, the higher is the recovery of copper and sulphur. The amount of ferric chloride for maximum recovery is found to be 3-5% more than the stoichiometric equivalent to form respective chlorides of the sulphides present in the concentrate other than the pyrite. With increase in concentration of free HCl in the leach upto 100g/l, the recovery of copper and sulphur increased but with further increase no perceptible influence on recovery is observed. A recovery of more than 99% copper and 92% chalcopyrite sulphur is obtained on leaching a low grade concentrate for 2 hr in a solution containing 520 g/l FeCl3 and 100g/l HCl with a ratio of FeCl3: CuFeS2=2.78:1 at a temperature of 105 ± 1°C. (Sarvashri G.Basu and P.K. Sinha, Senior Scientific Assistants; Shri S.C. Aush and Dr. N. Dhananjayan, Scientists; and Prof. V.A. Altekar, Director, National Metallurgical Laboratory, Jamshedpur

Recovery of non-ferrous-metals and elemental sulfur by ferric-chloride leaching of sulfide concentrates

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Determination of glyoxal and methylglyoxal in serum by UHPLC coupled with fluorescence detection

Glyoxal (GO) and methylglyoxal (MGO) are two important biomarkers in diabetes. Analytical methods for determination of GO and MGO in serum samples are either HPLC with UV-Vis (low sensitivity) or MS/MS (expensive) detection. These disadvantages have hampered the introduction of these biomarkers as a routine analyte for diabetes diagnostics into the clinical laboratory. In this study, we introduce a UHPLC method with fluorescence detection for the measurement of GO and MGO in serum samples by pre-column derivatization at neutral pH with 5, 6-diamino-2,4-dihydroxypyrimidine sulfate (DDP) to form lumazines. The method was validated as per FDA guidelines. Using this method, we have determined GO and MGO in a variety of animal serum samples, and for example, determined the GO and MGO concentration in adult bovine serum to be 852 ± 27 and 192 ± 10 nmol/L, respectively. In human serum, GO and MGO levels in non-diabetic subjects (n = 14) were determined to be 154 ± 88 and 98 ± 27 nmol/L, and in serum samples from subjects with diabetes (n = 14) 244 ± 137 and 190 ± 68 nmol/L, respectively. In addition, interference studies showed that physiological serum components did not lead to an artificial increase in the levels of GO and MGO