Accumulation of harmful chemicals is called bioaccumulation. It cannot be totally avoided in our bodies. But it can be reduced to some extent by following methods-
(i)We can avoid toxic chemical pesticides.
(ii)We can eat certified organic foods when possible. We should always wash fruits and vegetables before consuming.
(iii)We should choose fish wisely, as many contain unsafe levels of toxins.
(*Thank you very much and best of luck and don't forget to like my answer if you are satisfied:)*)