First report of the concentrations and implications of DDT residues in chicken eggs from a malaria-controlled area

• No published studies exist on DDT in chicken eggs from a malaria-controlled area.
• The median and maximum ΣDDT concentrations were 11,000 and 48,000 ng/g wet mass.
• The maximum residue limit was exceeded by a factor of 100.
• The calculated acceptable daily intake was not exceeded (3 eggs/week/60 kg bm).
• Reductions in DDT in the soil ingested by chickens may reduce human intake via eggs.

In malaria-endemic areas, where DDT is still used for vector control by indoor residual spraying (IRS), the concentrations of DDT in human blood and breast milk are high, and there are indications of human health impacts. To identify the possible avenues of exposure reduction, we created the concept of a Total Homestead Environment Approach (THEA). THEA characterizes the interactions between DDT, humans, and the biota within and around homesteads. One dietary route of human exposure and uptake of DDT, namely, chicken egg consumption, has to our knowledge never been studied. The ΣDDT in eggs from a DDT-sprayed village ranged between 5200 and 48,000 ng/g wm (wet mass), with a median of 11,000 ng/g wm. On a lipid mass-basis (lm), the mean ΣDDT for eggs from the sprayed village was 100,000 ng/g lm. The maximum egg concentration observed was three orders of magnitude higher than the median. The acceptable daily intake (ADI) was not exceeded based on the consumption of three eggs per week for a 60 kg person. This equates to an intake of 0.089 g DDT per person per year. Chicken egg consumption is therefore a possible target for exposure reduction, probably best achieved by reducing the DDT concentrations in soils.