The trend in the production of NPs is likely to lead to increasing amounts of nano-powders in the air, water and soil, which will consequently affect living organisms. Labielle et al. demonstrated that 25 % of Al(OH)₃-coated TiO₂ particles from sunscreens are dispersed as a stable colloid and become available to microorganisms and filter-feeders, while the remaining 75 % are probably incorporated into geogenic sediments, where they could become available to benthic fauna. Solar UV iradiation may penetrate as far as 20 m in the water column  and therefore photo-activate the dispersed particles, which may have an adverse effect on various aquatic organisms.

However, humans are not exposed to E171 in drinking water at any significant quantity over a long duration, so this potential effect is irrelevant to the human experience. It’s important to understand that a potential hazard is not the same thing as an actual risk. 

Lithopone B301, Lithopone B311 powder is also widely applied in paints and enamels