Algernon Africa

Pesticide exposure and blood endosulfan levels after first season spray amongst farm workers in the Western Cape, South Africa

The study investigated serum endosulfan changes resulting from occupational exposure to the pesticide on farms. Eight applicators and 17 non-applicators were tested (serum endosulfan, anthropometry, short exposure questionnaire) before and after the first day of seasonal spraying. Task-based job exposure matrix (JEM) estimates were calculated. Mean baseline serum endosulfan (530 ± 0.05 μ g/L) was high. Increases in post-spraying endosulfan levels (IPSE) were higher in applicators (mean = 60 ± 90 μ g/L) than in non-applicators (mean = 3.5 × 10− 6± 90.0 μ g/L) adjusting for age (β = 54.0, p = 0.162, R2 = 0.22). There was a weak positive relationship between IPSE and JEM estimates. IPSE occurred in applicators and non-applicators and were higher in applicators. The validity of the JEM weightings and characterization of other routes of pesticide exposure require further investigation.

Environmental monitoring of pesticide residues from farms at a neighbouring primary and pre-school in the Western Cape in South Africa

Concerns about pesticide drift from neighbouring vineyards affecting children attending school on a farm adjacent to an urban suburb of Cape Town, Western Cape in South Africa were investigated. The study involved a before-after design, measuring levels of environmental exposure before and during pesticide application activities on the neighbouring farms. Samples were collected in air, dust and grass cuttings at the preschool and primary school located on the farms during September-December in 2010 and tested for pesticides using multi-pesticide methods. Eleven different pesticides were detected in the various samples. Six of these chemicals (endosulfan, dimethomorph, penconazole, cyprodinil, boscalid and bromopropylate) were on the spraying schedules of the two farms neighbouring the schools and the timing and location of detection were generally consistent with farm application. Three pesticides detected (chlorpyrifos, cypermethrin, permethrin) are agents commonly used in household applications and one (pyriproxifen) is used in pet treatment agents. Kresoxim-methyl, the other pesticide detected, is likely to come from drift from other farms in the area. The concentration of pesticides was all lower than 0.1 μg/m(3) in air and 0.1 μg/kg in dust and grass apart from permethrin and cypermethrin. The findings confirm the presence of drift onto the school premises and concentrations found in this study were generally low in comparison to that detected in other studies. Regular monitoring to track the effectiveness of containment and mitigation measures that reduce drift is recommended.

Change in the quantity and acute toxicity of pesticides sold in South African crop sectors, 1994-1999

BACKGROUND South African pesticide market sales data, for two years, 1994 and 1999, were audited to identify change in total and per hectare mass sold and acute toxicity indicator (ATI) (kg sold/rat oral LD50) in the grape, pome, stone fruit, potato and wheat sectors. RESULTS Total pesticide sales (62%), amount per hectare (42%) and number of active ingredients (23%) increased in 1999 compared to 1994 with the grape fruit sector, the most significant contributor over the two years. Total (14%) and per hectare ATI (19%) decreased in 1999, but not substantially with the potato sector the most significant contributor. CONCLUSIONS Toxic pesticides were still used in 1999 which highlights a need to develop alternative agricultural and non-chemical pest control methods that reduce usage of pesticides.

Relationship between firewood usage and urinary Cr, Cu and As in informal areas of Cape Town

OBJECTIVES The study investigated whether wood usage by informal food vendors and household residents in Cape Town results in the absorption of arsenic (As), chromium (Cr) and copper (Cu) owing to release of these metals in the burning of chromated copper arsenate (CCA)-treated wood. METHODS The participants (N=78) selected included an equal number of food vendors and non-vendors from 2 informal settlements. All participants answered a questionnaire concerning exposure and were tested for urinary Cr, Cu and As, while the urine of 29 participants was also tested for toxic As (As(tox)). RESULTS Multivariate analysis showed that the time spent in close proximity to the wood, as well as the quantity of wood used for cooking and for household use, was weakly positively associated with urinary levels of As, Cr and the sum of As, Cr and Cu. CONCLUSIONS The study provides evidence that use of wood likely to contain CCA as a fuel for informal food outlets and household purposes may increase the absorption of inorganic As, Cu and Cr.

1 Exposure to CCA treated wood amongst food caterers and residents in informal areas of Cape Town

Objectives The study investigated if wood usage by street food caterers and household residents from informal settlements in Cape Town resulted in the absorption of Cr, Cu and As due to release of these metals from wood stocks treated with Chromated Copper Arsenate (CCA). Methods Participants (n = 78) selected included an equal number of food caterers and household residents from two informal settlement, one each located in an urban and a peri-urban area. All participants answered an exposure questionnaire and were tested for urinary Cr, Cu and As, while the urines of 29 participants were also tested for toxic As [As (tox)]. Results Urinary Cr and As exceeded the environmental exposure limit in 12% and 30% of participants respectively. As (tox) was detected in 30% of samples and 20.7% of As (tox) levels exceeded the environmental exposure limit of 6.4 µg/g creatinine. Urinary Cr, Cu, As and As (tox) levels were not significantly different in the two areas and amongst caterers and household residents after controlling for confounding (age, gender, education, smoking, eating fish and eating and drinking while cooking). The time spent on using wood as well as the quantity of wood used for catering and household use was weakly positively associated with urinary levels of As, Cr and the sum of As, Cr and Cu after controlling for confounding. Conclusions This study provides evidence of Cr and As exposure amongst both street caterers and household residents and that usage of wood stocks likely to contain CCA treated timber as a fuel for food catering and household purposes may increase absorption of inorganic As and Cr.

DISPOSAL OF UNWANTED PESTICIDES IN STELLENBOSCH, SOUTH AFRICA

BACKGROUND Unwanted pesticides in developing countries are major environmental health threats. This study followed-up a previous audit of unwanted and obsolete pesticides on farms in a rural district of South Africa six years after a National Retrieval Project (NPR) was undertaken. METHODS A descriptive survey of 37 farms that had been in possession of unwanted pesticides in a 1995 survey and a purposive sample of 34 neighbouring farms, was carried out. The survey data included farm details; details of unwanted pesticide stocks, volumes of empty containers and safety and hygiene of pesticide stores. In addition, management was asked if they had been informed about and participated in the 1997 NPR and similarly whether they were aware of the retrieval planned by the African Stockpiles Programme (ASP). RESULTS Forty (56%) farms were in possession of obsolete pesticides of which 24 (59%) were farms that had unwanted stocks in the previous survey. There were more than 9 tonnes of these pesticides, 50% more than in the previous survey, including 20 chemicals banned, withdrawn or restricted in South Africa or classified as WHO Class I toxicity. Over 2,800 kg of pesticides (30%) were not identifiable. None of the farms participated in the NPR, although 47 knew of the initiative. Only six farmers (9%) knew of the ASP initiative. Fifty-nine farms (83%) had empty containers on the premises. Most pesticide stores (67%) had floors contaminated with chemicals. CONCLUSION The survey found that despite the NPR, the problem of unwanted pesticides in the study area and probably throughout South Africa has deteriorated. National and international policies should control the problem at source and encourage more sustainable agriculture.