Surveillance for acute pesticide poisoning

Field surveys have emerged as valuable tools to complement clinical-based surveillance systems. Such surveys collect data directly from exposed communities and focus on acute pesticide poisoning. They invariably reveal a high level of poisoning in the communities studied (Kishi 22 , 2005; Murphy et al., 2002 23 ; Mancini 24 et al., 2005; Dasgupta 25 et al., 2007; PAN International 26 , 2010). A range of approaches for field surveillance exist: from the use of questionnaires, to open semi-structured group discussions (FAO/WHO 27 , 2009; FAO 28 , 2017). These can be complemented by biological testing, such as measuring acetylcholinesterase levels in the blood of exposed individuals (Cotton 29 et al., 2015) or the use of passive sampling techniques to identify the specific pesticides to which subjects have been exposed (Anderson 30 et al., 2014; Donald 31 et al., 2016). Community Pesticide Action Monitoring (CPAM) is a health monitoring tool developed by Pesticide Action Network Asia Pacific in the 1990s. It employs Participatory Action Research techniques and questionnaires to build up a picture of the local conditions under which pesticides have been used over the previous two years. It identifies routes of exposure, practices and behaviours that lead to exposure; social groups that are most at risk; the classes of pesticides, or even specific pesticides, that cause the most poisonings and the related health impacts. A series of CPAM surveys conducted between 2006 and 2009 in 21 areas in 13 African, Latin American and Asian countries estimated occupational poisoning rates of 47–59% (PAN International, 2010 26 ). CPAM, in common with most other questionnaire approaches, concentrates on signs and symptoms of acute pesticide poisoning which appear within 12–24 hours of exposure. Mild symptoms include headache, fatigue, dizziness, nausea, while more severe symptoms can include seizures, unconsciousness, incontinence and in extreme cases, death (Thundiyil 2 et al., 2008). While many of the signs and symptoms can have other causes (Litchfield 32 , 2005), the method depends on a ‘weight of evidence’ approach whereby multiple end users are consistently reporting similar acute effects within 24h of exposure to the same product and the evidence is consistent with other sources of information on the product, including toxicity data (FAO/WHO 33 , 2009).

Photo: Collecting data in Armenia. Credit PAN UK