In October 2010 we posted a comment about Chameleons Montessori, a private school located on Nitida Wine Farm in Durbanville.
A group of parents got together and formed the Galileo Group:
The summary report can be found below as follows :-
Introduction: Pesticides are chemicals that are used to protect crops against harmful pests. Pesticide drift is dependent on the wind and temperature conditions, distance from the spraying areas, the method of spraying and the volatility of the chemical sprayed. Potential health risks arising from exposure to pesticides in a school environment through pesticide drift is a concern facing children and employees at schools in rural farming locations worldwide. Such concerns about pesticide drift from neighboring vineyards affecting children attending school were raised by parents at the Chameleons School, situated in a rural farming district on the edge of an urban suburb of Cape Town, Western Cape in February 2010. The School consists of a Primary school, which is situated on a Farm (called Farm A for the report) adjacent to its vineyards, and a pre-school which is situated right on the border of another farm’s vineyard (called Farm B for this report).
Design: The study was planned as a before-after design, measuring levels of environmental exposure before, during and after pesticide application activities on the neighbouring farms. The hypothesis tested was that spraying on farm B would drift onto the Pre-school and that spraying on Farm A would drift onto the Primary school. Although a third phase was planned to sample after the spraying season, the findings from the first two phases appear sufficient to answer the study questions about spray drift without requiring a third follow up.
Methods: Three types of pesticide samples, namely air, dust and grass, were collected at the two Chameleons Montessori Schools (preschool and primary school) located on farm A. The sample collection was done at baseline before spraying was said to have started on the farms and then repeated during spraying in two separate samples. Samples were collected in air, dust and grass cuttings. The samples were tested for pesticides by an accredited laboratory using a multi-residue methods that tests for 126 different pesticides. Of these 126 pesticides, 7 were pesticides reported as applied on farms neighbouring the school. There were a further 7 pesticides reported as applied on the farm that could not be measured by the laboratory. These latter agents were pesticides of low acute toxicity and not noted in the literature as pesticide of concern.
1. The presence of pesticides
The study found the presence of pesticide residues in air, dust and grass samples both before spraying was reported to have started (baseline period) on farms and during the spraying period at both schools. The patterns of detection were broadly consistent with the use patterns reported on both farms A and B, with the timing of reported applications and with climatic conditions observed and reported in the area at the time of data collection. In particular, the findings of Boscalid (in air samples), Brompropylate (in dust samples), Dimethomorph (in dust samples) and penconazole (in air and in grass samples) were all consistent by timing and location with evidence of spray drift. These findings suggest there is drift taking place from neighbouring farms for these pesticides.
The presence of Kresoxim-methyl could not be directly explained by spray on neighbouring farms but followed a pattern of being absent at baseline and being present in dust and air samples during the spray season. Kresoxim-methyl is registered for use on vineyards and may have drifted onto the School from farms other than those on the school boundaries.
Endosulfan was detected in air and grass samples, though no pattern of timing consistent with a date of application was clear and, although it was initially on the spray list to be applied for farm B, both farms indicated they did not apply it. However, given its persistence and it use solely as an agricultural chemical, it is very likely to arise from agricultural application on farms in the area, even if not from neighbouring farms. These findings involving endosulfan and Kresoxim-methyl may signal a wider problem of environmental pesticide drift in the entire farming areas, not specific to the Chameleons site, which may warrant separate investigation.
A further set of pesticides detected both during the non-spraying baseline and the spraying period (chlorpyrifos, cypermethrin, permethrin and pyriproxyfen) were agents that probably were present as a result of non-agricultural applications for household, veterinary or garden purposes. There was no temporal or geographical patterning consistent with external application. These findings suggest these pesticides were present as a result of household pesticide application.
The Quality Assurance measurements suggest that the laboratory did not over-identify pesticides, and achieved adequate precision in its estimates of concentrations.
2. The concentrations of pesticides detected and health implications
The concentrations of pesticides found in this study were generally low in comparison to similar studies overseas. There are almost no standards available globally for permissible exposures to the pesticides detected in this study in grass, dust and air, the only exception being the USEPA standard for endosulfan in air. The levels in this study were well below that EPA standard for endosulfan. Concentrations of chlorpyrifos, endosulfan, cypermethrin and permethrin detected in the schools were generally lower, or of the same order of magnitude as samples in control sites from other studies, or comparable to ambient concentrations found in a Canadian study of environmental air sampling. The control site at UCT of dust in offices also demonstrated levels of chlorpyrifos, cypermenthrin and permethrin higher than those detected in the study at the schools. In no cases were lower concentrations reported in comparable studies.
Although not directly comparable, Maximum Residue Levels for pesticides on grapes permitted by the Department of Health were higher than concentrations found in grass samples at both schools. It is therefore reasonable to infer that the pesticide concentrations detected in grass were low. Nonetheless, given the lack of health based-standards for all but endosulfan, and consistent with the precautionary principle, it would be prudent to take action to reduce exposures as far as possible.
Conclusions: Firstly, the study has suggested that there is evidence for spray drift into the school, as well as potential non-agricultural routes for exposure (use of household pesticides and ornamental or veterinary pesticides). Secondly, the concentrations detected in air, dust and grass are low relative to studies published in other countries and to analogous benchmarks. Thirdly, the detection of pesticides that were not applied on neighbouring farms but which are in use in agricultural production in the area, may signify a broader problem of environmental pesticide drift which requires wider investigation by the relevant authorities. The data are sufficient convincing to suggest that there is no need for a third phase of sampling and that resources could be better spent on monitoring interventions to reduce exposure.
There are possible ways to reduce pesticide drift and its consequences which include use of application methods with less potential for drift, restriction of applications when climatic conditions facilitate drift, establishing barriers on the school perimeter, administrative controls to reduce spraying times or outdoor activity during spraying, targeted housekeeping measures to clear pesticides in dust, avoiding use of domestic pest control agents containing pesticides of concern and education of staff and contractors. In the long-term, changes to the form of agricultural production, including reduced use of pesticides, use of Integrated Pest Managmeent (IPM) and movement to organic agriculture will reduce the risk of drift. We also recommend the school introduce regular monitoring to track the effectiveness of containment and mitigation measures that are implemented. We also propose that the authorities investigate the broader problem of pollution from spray drift affecting the area generally, given evidence suggesting that pesticides were drifting into the school from farms other than those adjacent to the school.
BANNED worldwide inc in South Africa.
CHLORPYRIFOS is a toxic organophosphate poison.
BANNED for use in houses, parks and schools in South Africa from May 2010. In other words there should not be residues in and around the school insofar household & garden purposes are concerned as its been banned for such use. It is however not banned for Agricultural use. More than likely Nitida has been using chrlorpyrifos. Most wine / grape farmers do use it - so I dont see why Nitida has not used it.
KRESOXIM METHYL is a known carcinogen