Modelling potential human exposure to the urease inhibitor NBPT through the environment-food pathway.

The urease inhibitor N-(n-butyl) thiophosphoric triamide (NBPT) has recently attracted a lot of attention attributing to its efficiency in reducing ammonia loss from urea fertiliser applied to temperate grassland soils. Ammonia gas lost to the environment causes soil acidification, eutrophication and contributes to global warming through increased greenhouse gas emissions and ozone layer depletion. The active chemical NBPT blocks the soil microbial enzyme (urease) and reduces ammonia emission.