Mohamed Aqiel Dalvie

Contamination of rural surface and ground water by endosulfan in farming areas of the Western Cape, South Africa

BackgroundIn South Africa there is little data on environmental pollution of rural water sources by agrochemicals.MethodsThis study investigated pesticide contamination of ground and surface water in three intensive agricultural areas in the Western Cape: the Hex River Valley, Grabouw and Piketberg. Monitoring for endosulfan and chlorpyrifos at low levels was conducted as well as screening for other pesticides.ResultsThe quantification limit for endosulfan was 0.1 μg/L. Endosulfan was found to be widespread in ground water, surface water and drinking water. The contamination was mostly at low levels, but regularly exceeded the European Drinking Water Standard of 0.1 μg/L. The two most contaminated sites were a sub-surface drain in the Hex River Valley and a dam in Grabouw, with 0.83 ± 1.0 μg/L (n = 21) and 3.16 ± 3.5 μg/L (n = 13) average endosulfan levels respectively. Other pesticides including chlorpyrifos, azinphos-methyl, fenarimol, iprodione, deltamethrin, penconazole and prothiofos were detected. Endosulfan was most frequently detected in Grabouw (69%) followed by Hex River (46%) and Piketberg (39%). Detections were more frequent in surface water (47%) than in groundwater (32%) and coincided with irrigation, and to a lesser extent, to spraying and trigger rains. Total dietary endosulfan intake calculated from levels found in drinking water did not exceed the Joint WHO/FAO Meeting on Pesticide Residues (JMPR) criteria.ConclusionThe study has shown the need for monitoring of pesticide contamination in surface and groundwater, and the development of drinking water quality standards for specific pesticides in South Africa.

Long-term respiratory health effects of the herbicide, paraquat, among workers in the Western Cape

OBJECTIVE: To evaluate the possible effects of paraquat spraying among workers on deciduous fruit farms in the Western Cape, South Africa. Paraquat is a commonly used herbicide world wide and is a well documented cause of pulmonary fibrosis in studies of laboratory animals and in humans after exposure to a high dose (usually accidental or as parasuicide). The respiratory effects of long term, low dose exposure to paraquat have not been fully evaluated. METHODS: A cross sectional study of 126 workers. Administered questionnaires generated information on exposure, respiratory symptoms, and potential confounding variables. Spirometry and gas transfer were measured and chest radiographs performed. Oxygen desaturation on exercise testing was by oximetry during a modified stage one exercise test. RESULTS: No association was found between long term exposure to paraquat and reported symptoms, spirometry (forced vital capacity (FVC), forced expiratory volume in 1 second (FEV1), FEV1/FVC) and gas transfer (TLCO and KCO) or chest radiography. Multivariate analysis showed a significant relation between measures of long term exposure to paraquat and arterial oxygen desaturation during exercise independent of short term exposure. CONCLUSION: Previous studies have not shown a significant relation between measures of exposure to paraquat and standard tests of lung function. Arterial oxygen desaturation during exercise represents a more sensitive test. The findings indicate that working with paraquat under usual field conditions is associated with abnormal exercise physiology in a dose dependent fashion independent of recent exposure and acute poisoning events.

Differences in the carcinogenic evaluation of glyphosate between the International Agency for Research on Cancer (IARC) and the European Food Safety Authority (EFSA)

The International Agency for Research on Cancer (IARC) Monographs Programme identifies chemicals, drugs, mixtures, occupational exposures, lifestyles and personal habits, and physical and biological agents that cause cancer in humans and has evaluated about 1000 agents since 1971. Monographs are written by ad hoc Working Groups (WGs) of international scientific experts over a period of about 12 months ending in an eight-day meeting. The WG evaluates all of the publicly available scientific information on each substance and, through a transparent and rigorous process,1 decides on the degree to which the scientific evidence supports that substances potential to cause or not cause cancer in humans. For Monograph 112,2 17 expert scientists evaluated the carcinogenic hazard for four insecticides and the herbicide glyphosate.3 The WG concluded that the data for glyphosate meet the criteria for classification as a probable human carcinogen . The European Food Safety Authority (EFSA) is the primary agency of the European Union for risk assessments regarding food safety. In October 2015, EFSA reported4 on their evaluation of the Renewal Assessment Report5 (RAR) for glyphosate that was prepared by the Rapporteur Member State, the German Federal Institute for Risk Assessment (BfR). EFSA concluded that ‘glyphosate is unlikely to pose a carcinogenic hazard to humans and the evidence does not support classification with regard to its carcinogenic potential’. Addendum 1 (the BfR Addendum) of the RAR5 discusses the scientific rationale for differing from the IARC WG conclusion. Serious flaws in the scientific evaluation in the RAR incorrectly characterise the potential for a carcinogenic hazard from exposure to glyphosate. Since the RAR is the basis for the European Food Safety Agency (EFSA) conclusion,4 it is critical that these shortcomings are corrected. EFSA concluded ‘that there is very limited evidence for an association between glyphosate-based formulations …

Disposal of obsolete pesticides, the case of Ethiopia

Ethiopia has accumulated obsolete pesticide stocks since pesticides were first imported in the 1960s due to prolonged storage of pesticides, inappropriate storage conditions because of poor storage facilities, the lack of trained staff and lack of national legislation for pesticide registration and monitoring system of pesticide use in the country. The first pesticide inventory conducted in 1995 led by FAO in collaboration with the government of Ethiopia had identified about 426 tonnes of obsolete pesticides mainly on state-owned agricultural farms and held by the Ministry of Health. However, these stocks have increased to over 1500 tonnes (including 200 active ingredients) as found in a detailed inventory conducted in 1999. The stocks included organochlorines (258.3 tonnes), organophosphates (155.4 tonnes), carbamates (58.5 tonnes), coumarines (14.9 tonnes), inorganics (30.2 tonnes), others (257.2 tonnes), mixed pesticides (70.4 tonnes) and unknown pesticides (307.1 tonnes) including both liquid and solid state formulations. The obsolete organochlorine pesticides stocks were mostly pesticides such as chlordane, DDT, dieldrin and lindane that are banned or restricted in most countries. The highest amount of a single active ingredient found was the organophosphate insecticide pirimiphos methyl (172.1 tonnes). All these stocks were disposed of in the first phase of disposal in Finland (during 2000-2003) by the hazardous waste management company Ekokem at a cost of about US

Assessing the management of healthcare waste in Hawassa city, Ethiopia

4.44 million. Another 1000 tonnes of obsolete pesticides have been identified and are currently being eliminated in a second disposal phase at a total cost of US

AGRICOH: A Consortium of Agricultural Cohorts

8,135,500. Along with the disposal process, a number of activities are being implemented to prevent future pesticides accumulation. These activities include the development and enforcement of pesticide policy, the implementation of Integrated Pest Management (IPM) and Integrated Vector Management (IVM), capacity building in terms of providing professional trainings, creating awareness among stakeholders on the environmental and human health hazard posed by obsolete pesticides as well as other actions to prevent their accumulation and enforcement of national legislations and policies related to pesticides use. However, pesticide use in the country is increasing. For instance, 12 years of pesticides import data (1996-2007) by the Ministry of Agriculture shows that 2973 tonnes of pesticides were imported between 1996-1998, 3670 tonnes between 1999-2001, 5079 tonnes between 2002-2004 and 8302 tonnes between 2005-2007. Moreover, 6 years of insecticide import data (1996/97-2001/02) by the Ministry of Health shows that around 919 tonnes of insecticides were imported between 1996/97-1997/98, 812 tonnes between 1998/99-1999/00 and 970 tonnes between 2000/01-2001/02 for malaria and other vector borne diseases control.

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

Inadequate management of healthcare waste is a serious concern in many developing countries due to the risks posed to human health and the environment. This study aimed to evaluate healthcare waste management in Hawassa city, Ethiopia. The study was conducted in nine healthcare facilities (HCFs) including hospitals (four), health centres (two) and higher clinics (three) in two phases, first to assess the waste management aspect and second to determine daily waste generation rate. The result showed that the median quantity of waste generated at the facilities was 3.46 kg bed(-1) day(-1) (range: 1.48-8.19 kg bed(-1) day(-1)). The quantity of waste per day generated at a HCF increased as occupancy increased (p < 0.001). The percentage hazardous waste generated at government HCFs was more than at private HCFs (p < 0.05). The proportion of hazardous waste (20-63.1%) generated at the different HCFs was much higher than the WHO recommendation (10-25%). There was no waste segregation in most HCFs and only one used a complete color coding system. Solid waste and wastewater were stored, transported, treated and disposed inappropriately at all HCFs. Needle-stick injuries were prevalent in 25-100% of waste handlers employed at these HCFs. Additionally, low levels of training and awareness of waste legislation was prevalent amongst staff. The study showed that management of healthcare waste at HCFs to be poor. Waste management practices need to be improved through improved legislation and enforcement, and training of staff in the healthcare facilities in Hawassa.Inadequate management of healthcare waste is a serious concern in many developing countries due to the risks posed to human health and the environment. This study aimed to evaluate healthcare waste management in Hawassa city, Ethiopia. The study was conducted in nine healthcare facilities (HCFs) including hospitals (four), health centres (two) and higher clinics (three) in two phases, first to assess the waste management aspect and second to determine daily waste generation rate. The result showed that the median quantity of waste generated at the facilities was 3.46 kg bed(-1) day(-1) (range: 1.48-8.19 kg bed(-1) day(-1)). The quantity of waste per day generated at a HCF increased as occupancy increased (p < 0.001). The percentage hazardous waste generated at government HCFs was more than at private HCFs (p < 0.05). The proportion of hazardous waste (20-63.1%) generated at the different HCFs was much higher than the WHO recommendation (10-25%). There was no waste segregation in most HCFs and only one used a complete color coding system. Solid waste and wastewater were stored, transported, treated and disposed inappropriately at all HCFs. Needle-stick injuries were prevalent in 25-100% of waste handlers employed at these HCFs. Additionally, low levels of training and awareness of waste legislation was prevalent amongst staff. The study showed that management of healthcare waste at HCFs to be poor. Waste management practices need to be improved through improved legislation and enforcement, and training of staff in the healthcare facilities in Hawassa.

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

AGRICOH is a recently formed consortium of agricultural cohort studies involving 22 cohorts from nine countries in five continents: South Africa (1), Canada (3), Costa Rica (2), USA (6), Republic of Korea (1), New Zealand (2), Denmark (1), France (3) and Norway (3). The aim of AGRICOH, initiated by the US National Cancer Institute (NCI) and coordinated by the International Agency for Research on Cancer (IARC), is to promote and sustain collaboration and pooling of data to investigate the association between a wide range of agricultural exposures and a wide range of health outcomes, with a particular focus on associations that cannot easily be addressed in individual studies because of rare exposures (e.g., use of infrequently applied chemicals) or relatively rare outcomes (e.g., certain types of cancer, neurologic and auto-immune diseases). To facilitate future projects the need for data harmonization of selected variables is required and is underway. Altogether, AGRICOH provides excellent opportunities for studying cancer, respiratory, neurologic, and auto-immune diseases as well as reproductive and allergic disorders, injuries and overall mortality in association with a wide array of exposures, prominent among these the application of pesticides.

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

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.

Urinary dialkyl phosphate levels before and after first season chlorpyrifos spraying amongst farm workers in the Western Cape, 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.