es6b02477_si_001.pdf (628.31 kB)
Impacts of (Nano)formulations on the Fate of an Insecticide in Soil and Consequences for Environmental Exposure Assessment
journal contribution
posted on 2016-09-20, 00:00 authored by Melanie Kah, Anne-Kathrin Weniger, Thilo HofmannThe development of
nanopesticides has recently received an increased
level of attention. However, there are very few data about the environmental
fate of these new products, and it is not known whether nanoformulations
can be evaluated within the current pesticide regulatory framework.
Sorption and degradation parameters of the insecticide bifenthrin
were measured in two soils for (i) the pure active ingredient, (ii)
three nanoformulations, and (iii) a commercially available formulation.
In most cases, fate parameters derived for the nanopesticides were
significantly different from those derived for the pure active ingredient
(factors of up to 10 for sorption and 1.8 for degradation), but discrepancies
were not easy to relate to the characteristics of the nanocarriers.
In some cases, differences were also observed between the commercial
formulation and the pure active ingredient (factors of up to 1.4 for
sorption and 1.7 for degradation). In the regulatory context, the
common assumption that formulations do not influence the environmental
fate of pesticide active ingredients after application seems therefore
not always adequate. In the absence of direct measurement, an inverse
modeling approach was successfully applied to evaluate the durability
of the formulations in soil (release half-life ranged between 11 and
74 days). Predicted groundwater concentrations very much depended
on the modeling approach adopted but overall suggest that the nanoformulations
studied could reduce losses to groundwater.