Undereporting of acute pesticide poisoning in Tanzania: modelling results from two cross-sectional studies.

BACKGROUND: Acute pesticide poisoning (APP) is known to cause serious injuries to end users globally but the magnitude of this problem in Tanzania is not well known. This study aimed to determine the extent and pattern of underreporting of APP in Tanzania to inform the development of a surveillance system and appropriate interventions. METHODS: This study integrates findings from two recent Tanzanian studies. A household survey established the proportion of poisoned farmers in a typical rural area who reported to hospital for a pesticide poisoning. Only 5 of the 112 farmers who reported attending hospital due to poisonings could be traced in medical records at the facilities they claimed to have attended. The 95% confidence interval for this ratio (5/112) was used to generate a high and low boundary for the estimates. Three under-estimation factors were generated for sensitivity analysis to adjust for under-reporting. A review of health facilities in three regions of Tanzania collected prospective data on admissions for APP in 2006 to generate population-based APP incidence rates stratified by circumstances of poisoning (occupational, accidental, suicide, and unknown). Sensitivity analysis was conducted involving adjustment for high and low boundaries of the under-reporting of occupational APP and an adjustment for different scenario allocations of cases with 'unknown' circumstances to different combinations of known circumstances. RESULTS: The study estimated the rate of occupational poisoning as ranging from 11.3-37.7 cases/million to 84.3-279.9 cases per million. The rate of all poisonings (occupational and non-occupational) ranged from 24.45-48.01 cases per million to 97.37-290.29 cases per million. Depending on the choice of scenario and under-reporting correction factor used, occupational APP could comprise from 52.2 to 96% of all APP cases. CONCLUSION: The study confirms that data on APP in Tanzanian hospitals are poorly reported and that occupational circumstances are particularly overlooked in routine facility-based surveillance. Occupational APP needs to be taken more seriously in addressing prevention measures. A comprehensive surveillance system for APP should consider multiple data sources including community self-reporting in order to achieve better coverage.

Pesticide retailers' knowledge and handling practices in selected towns of Tanzania.

BACKGROUND: Approximately 300 pesticide retailers are currently registered in Tanzania. Inadequate knowledge and unsafe handling practices among retailers may contribute to human pesticide exposure and environmental contamination. This study investigated pesticide retailers' qualifications, work experience, safety practices and the products distributed so as to identify opportunities for preventing Acute Pesticide Poisoning (APP). METHODOLOGY: In 2005, employees of pesticide retail firms in six Tanzanian towns were surveyed using a semi-structured questionnaire and physical inspection of premises. In addition, information on products distributed in 2004 and 2005 was collected from Arusha and Arumeru firms to assess potential risk posed for end-users. RESULTS: More than half of the participating firms (58.6%) were not registered. Most agents on sale in Arusha and Arumeru were hazardous products including WHO Class I and II products (61.7%) and the mean number of cholinesterase inhibiting agents was 5.8 (range 2-8). Major deficiencies found included semi-trained staff (52%), lack of first-aid kits (38.6%), repacking and decanting of pesticides into smaller unlabelled containers (25.3%), lack of fire-fighting equipment (22.6%) and distribution of unregistered products (9.3%). Compared to unregistered companies, those companies that were registered were more likely to report practicing safe container disposal (40% versus 19%; p = 0.06) and to have an absence of leaking containers (36% versus 15%; p = 0.04). CONCLUSION: Pesticide distribution in Tanzania was accompanied by many unsafe practices that may contribute to the burden from APP, not only affecting the distributors but also farmers who buy and use these products. Market pressures appear to be encouraging decanting of pesticides to enable retailers to make profits. Registration of firms appears to be associated with safer practices. Comprehensive interventions to strengthen enforcement mechanisms by increasing the number of pesticide inspectors, ensuring adequate financial support for enforcement activities and providing training opportunities for pesticide retailers and the end users are strongly recommended.

Farmers' knowledge, practices and injuries associated with pesticide exposure in rural farming villages in Tanzania.

BACKGROUND: Pesticides in Tanzania are extensively used for pest control in agriculture. Their usage and unsafe handling practices may potentially result in high farmer exposures and adverse health effects.The aim of this study was to describe farmers' pesticide exposure profile, knowledge about pesticide hazards, experience of previous poisoning, hazardous practices that may lead to Acute Pesticide Poisoning (APP) and the extent to which APP is reported. METHODS: The study involved 121 head- of-household respondents from Arumeru district in Arusha region. Data collection involved administration of a standardised questionnaire to farmers and documentation of storage practices. Unsafe pesticide handling practices were assessed through observation of pesticide storage, conditions of personal protective equipment (PPE) and through self-reports of pesticide disposal and equipment calibration. RESULTS: Past lifetime pesticide poisoning was reported by 93% of farmers. The agents reported as responsible for poisoning were Organophosphates (42%) and WHO Class II agents (77.6%).Storage of pesticides in the home was reported by 79% of farmers. Respondents with higher education levels were significantly less likely to store pesticides in their home (PRR High/Low = 0.3; 95% CI = 0.1-0.7) and more likely to practice calibration of spray equipment (PRR High/Low = 1.2; 95% CI = 1.03-1.4). However, knowledge of routes of exposure was not associated with safety practices particularly for disposal, equipment wash area, storage and use of PPE . The majority of farmers experiencing APP in the past (79%) did not attend hospital and of the 23 farmers who did so in the preceding year, records could be traced for only 22% of these cases. CONCLUSIONS: The study found a high potential for pesticide exposure in the selected community in rural Tanzania, a high frequency of self-reported APP and poor recording in hospital records. Farmers' knowledge levels appeared to be unrelated to their risk. Rather than simply focusing on knowledge-based strategies, comprehensive interventions are needed to reduce both exposure and health risks, including training, improvements in labeling, measures to reduce cost barriers to the adoption of safe behaviours, , promotion of control measures other than PPE and support for Integrated Pest Management (IPM).