Chemical agents that can occur as by-products of industrial pollution and be consumed by humans are

Polychlorinated Biphenyls.

Explanation:

Polychlorinated Biphenyls are man-made chemicals. They are solids, and oily liquid in structure with no taste or small, yellow to clear in color. PCBs are present as a mixture, and very stable at an extreme pressure, and temperature. Basically they are used in electrical equipment such as transformers, and capacitors. High level of PCBs can cause broad spectrum of effects in humans, for example:

1) Increase some liver enzyme level, and cause hepatic damage.

2) Respiratory problems.

3) Dermal lesions.

the atomic mass is the bottom number on the element.

-steel jelly