Exploring Aflatoxin Prevention and Control Practices in Banke, Nepal

Background Aflatoxins are harmful to animals and humans. Much is unknown about the determinants of aflatoxin exposure, and how specific agricultural practices may lead to, or help limit, food contamination and diet exposure. Based on prior studies, chronic consumption of aflatoxins may be a public health concern in Nepal. Objective To explore common agricultural practices that may be associated with aflatoxin (AFB1) exposure in pregnant women. Methods This study uses data from an ongoing birth cohort study (n=1675) in 17 Village Development Committees in the Banke District of Nepal. At recruitment (pregnancy), a questionnaire evaluated drying and storage practices for high risk aflatoxin foods such as rice, pulses, wheat, corn and groundnuts. Farmers were asked about drying, storage structures, storage period, storage problems and insecticide/fungicide usage during storage. Aflatoxin exposure during pregnancy was measured in venous blood samples from participants. Questionnaire data was available for all participants, while AFB1 results were available for half of the participants. AFB1 results (n=810) were divided into quartiles for analysis. Descriptive statistics and bivariate analyses were used to explore how agricultural practices may be associated with AFB1 exposure levels. All analyses were conducted with Stata® SE version 14. Results Detectable levels of aflatoxin were found in 95% samples, with a mean serum AFB1 concentration of 4.67 (range: undetectable to 147) pg/mg‐albumin and a geometric mean concentration of 2.11 (CI: 1.95–2.28) pg/mg‐albumin. Of the participants, 76% produced rice, 51% pulses, 61% wheat, 25% corn and only 2% produced groundnuts. The majority of producers reported drying their crops immediately after harvest (from 86% for corn and almost 100% for rice). Participants reported drying most rice and wheat on the field; pulses on the field, on dirt and on plastic sheets; and corn and groundnuts on dirt and plastic sheets. The most common method for verifying crop dryness was visual inspection (65% rice, 45% pulses, 52% wheat, 63% corn) for all crops, except for groundnuts, for which cracking sound with teeth and visual inspection were the most commonly used methods. Method of inspection was significantly associated with AFB1 levels for wheat (p=0.023). Indoor mud bins (Dehari) were the most commonly used storage structures for rice, pulses and wheat, while sealed containers (made of plastic, metal or glass) and plastic bags were the most commonly used storage structures for corn and groundnuts. The majority of participants stored rice, pulses and wheat, typically in Deharis, for very long periods of time (≈one year or more). Storage period was significantly associated with AFB1 levels for rice (p=0.041). Insects were reported as the most common storage problem followed by rodents and mold. Very few farmers used insecticides in or around the storage area for rice, pulses and wheat, and use of fungicides in and or around the storage area was essentially non‐existent. Conclusion The presence of aflatoxin exposure was widespread among the sub‐sample with AFB1 results. Participants produced at least one food considered to be at high risk for aflatoxin contamination. A few practices, such as method for dryness verification and storage period were associated with AFB1 for certain crops. Future work will study additional variables to identify potential risk factors for aflatoxin exposure in this population. Support or Funding Information Support for this research was provided by the Feed the Future Innovation Lab for Nutrition, which is funded by the United States Agency for International Development. The opinions expressed herein are solely those of the authors.