Complex sentence: Independent studies show that while the photodegradation half-life time of most neonicotinoids is around 34 days when exposed to sunlight, it might take up to 1,386 days (3.8 years) for these compounds to degrade in the absence of sunlight and micro-organism activity.
Split into simpler sentences: Independent studies show that the photodegradation half-life time of most neonicotinoids is around 34 days when exposed to sunlight. However, it might take up to 1,386 days (3.8 years) for these compounds to degrade in the absence of sunlight and micro-organism activity.