Challenges and Research Needs for Risk Assessment of Pesticides for Registration in Africa

Abstract

Risk assessment is necessary for registration and risk management of new pesticides. The aim of this article is to discuss challenges that risk assessors in Africa face when conducting risk assessment of pesticides. Risk assessment requires toxicity assessment, environmental fate studies, and the use of models for occupational, dietary, residential, and environmental exposure assessments. Toxicity studies are very costly with the result that toxicity data used to register pesticides in Africa are often sourced from northern hemisphere countries. Assessors also often use exposure modeling results from the northern hemisphere. This is not an ideal approach as occupational exposure is influenced by agricultural practices, climatic conditions, and other factors. Furthermore, residential exposure models require time-locationactivity information, exposure factors, and toxicokinetic rate constants for particular pesticides. Dietary exposure assessment needs accurate and comprehensive local food consumption data. Authorities in African countries should therefore generate the required data, despite these being very costly and tedious. Authorities should also provide guidance on the type of models and standard scenarios for estimating predicted environmental concentrations in various environmental compartments. It is recommended that higher educational institutions in Africa should incorporate risk assessment in general and pesticide toxicity and exposure models in particular in their curricula.

A Critical Review of the Status of Pesticide Exposure Management in Malawi

“…Risk assessment also results in the establishment of MRLs which should ideally be determined using generally acceptable practices (GAP) in locally produced agricultural commodities from local field trials covering the local range of climates, growing practices, crops, and cultivars [60]. Therefore, capacity is needed to allow the Minister of Agriculture to prepare MRLs based on local data, and not based on foreign data or on MRLs developed by the Codex Alimentarius Commission.…”

Characterisation of Neonicotinoid Insecticides in the Cocoa-producing Owena River Basin of Nigeria by a QuEChERS Method Coupled to Liquid Chromatography-Tandem Mass Spectrometry

“…The nature of the task of quantitative phenomenological modelling is challenging and colossal. These exercises have been attempted by Wood and Goulson (2017) and Utembe and Gulumian (2015).…”

A Systematic Framework for Collecting Site-Specific Sampling and Survey Data to Support Analyses of Health Impacts from Land-Based Pollution in Low- and Middle-Income Countries

“…Characterizing exposures and intake requires information on chemical concentration, frequency and duration of exposure, and various exposure factors such as behavior, time and activity patterns, and contact or intake rates [ 18 , 19 ]. Standardized exposure factors have not been derived for application in LMICs as they have in other countries [ 15 , 16 , 18 , 20 , 21 , 22 ]. Differing dietary habits, earthen floor housing, climate and time spent outdoors, local environments, dusty conditions during particular times of the year and unpaved roads, and other factors and behaviors all imply that exposure factors, while unknown, are likely to differ from data obtained from high-income countries [ 23 , 24 ].…”

“…Moreover, while standardized exposure factors (e.g., intake rates, consumption patterns, individual behaviors, lifestyle factors, etc.) are fairly well-described in a few high-income countries, there is a lack of such standardized data from LMICs [ 15 , 16 ].…”