Effect of Marine Pollution on Man!
Once some of the pollutant gets ingested by marine organisms, the major concern of man has been the possibility of this pollutant appearing on his dinner table and causing a pathogenic response.
Obviously if a fish ingests a pollutant and a human eats that fish, then that person will get ingested a dose of that pollutant and there will probably be some danger. The question is, “How much?” In order to arrive at an approximation of the actual amount of undesired material finding its way into the reader’s stomach, one must be able to follow the pollutant through a number of steps.
Most organisms living in the sea tend to concentrate materials existing in the sea to much greater values than they have been in the ocean itself. For example, a diatom, a small form of marine algae having silicate frustules, is having a body concentration of silicon about 40 thousand times as great as the oceanic waters from which the organism derives all of its material. Thus, the diatom concentrates silicon very effectively so that if we are diatoms, a large portion of our diet would be glassy.
Similarly, other organisms, including fish, will concentrate other materials even if these do not naturally occur in the environment. But this amplification or concentration does not stop with one step. We must continually keep in mind the fact that an organism does not exist by itself in the marine environment.
Any organism has been dependent upon many other organisms for its existence. An edible fish, for example, might very well subsist on smaller fish which, in turn, .might subsist on small zooplankton (small floating forms of animal life), which, in turn, may subsist on phytoplankton (forms of floating plant life).
There may be 5 to 10 individual links in a food chain leading to man, and there has been the distinct possibility that for each one of these links a concentration of the pollutant occurs. Hence, the total pathway to man for the pollutant might be a rather tortuous one, but it might result in a very high concentration of the pollutant material in the fish.
This in itself may be of no concern to the individual unless he ingests the fish and if so, how often and how much he consumes. It has been not enough simply to know that there has been some pollutant present in marine organisms; one should also know how much is present, and in addition two other facts have been required.
This first has been the accepted maximum level of ingestion of the pollutant before harm results, and the second has been the amount of fish that can be eaten before this level gets reached. In this way it might very well be possible to have a particular kind of fish one or two times a year with perfect safety, while if it has been eaten once a day, it might very well have a toxic effect.