Many waste substances that have been disposed of into the sea can cause a variety of acute and chronic health conditions. The concentration, biological form, chemical form, physical form and survival of these pollutants are all aspects of whether humans would be exposed to them. There are two major ways in which humans can be contaminated by these pollutions. The first is direct contact either through the skin, lungs or by being digested; swimming in polluted sea water would be a good way of being contaminated by a direct contact method. The second way is an indirect way such as consuming plants or animals that have come from the contaminated area.

Indirect contamination is a significant way in which humans can be exposed to toxic organic chemical and metals because they can be bio accumulated in plants and animals that humans consume. Direct contamination is a less significant way in which humans can be exposed to toxic organic chemical and metals because they tend to be in sea water in low concentration. In the case of pathogens both methods can be significant because only small numbers of micro organisms to induce disease and because micro organisms can reproduce in infected animals and the environment.