Radioactive Contaminants

Since it was discovered that ionizing radiation produces detrimental biological effects, many national and international groups have studied the sources and levels of radiation to which the human population is exposed, and have estimated the corresponding biological effects. Some of these groups have also been responsible for establishing permissible levels of exposure. Consequently, there is a large body of information on the biological effects of ionizing radiation. The Subcommittee on Radioactivity in Drinking Water has relied heavily on the reports of those other groups and has abstracted and summarized pertinent sections. In some cases it was possible to take new published and unpublished information into account in this assessment of the probable effects of the radioactivity in drinking water on the population of the United States.

Among the groups whose reports were used were: the National Academy of Sciences Advisory Committee on the Biological Effects of Ionizing Radiation (BEIR), the United Nations Scientific Committee on the Effects of Atomic Radiation (UNSCEAR), the International Commission on Radiological Protection (ICRP), and the National Council on Radiation Protection and Measurements (NCRP).

Since it was discovered that ionizing radiation produces detrimental biological effects, many national and international groups have studied the sources and levels of radiation to which the human population is exposed, and have estimated the corresponding biological effects. Some of these groups have also been responsible for establishing permissible levels of exposure. Consequently, there is a large body of information on the biological effects of ionizing radiation. The Subcommittee on Radioactivity in Drinking Water has relied heavily on the reports of those other groups and has abstracted and summarized pertinent sections. In some cases it was possible to take new published and unpublished information into account in this assessment of the probable effects of the radioactivity in drinking water on the population of the United States.

https://www.ncbi.nlm.nih.gov/books/NBK234160/

Chemical Contamination

The phrase 'chemical contamination' is used to indicate situations where chemicals are either present where they shouldn’t be, or are at higher concentrations than they would naturally have occurred. Chemical contaminants can be found as organic and inorganic molecules in mass produced products used day to day by almost everybody. These include plastics, resins, pharmaceuticals, disinfectants, deodorants, detergents, petroleum products, road runoff, pesticides and biocides, along with the results of land fill and incineration

Some contaminants can increase bacteria growth and oxygen consumption within a waterway. In extreme cases, such as a large spill of sewage or milk, low oxygen conditions may kill mahinga kai species. Lower levels of nutrient contamination in waterways can result in eutrophication. Most eutrophication is due to the inorganic nutrients nitrate and phosphate that induce the growth of algae. The algae subsequently die, resulting in more organic matter and low oxygen conditions.

• This takes place when unwanted chemicals enter the foodstuff during

•  Food preparation, for example, oil, cleaning chemicals (residues found in pots and pans that have not been cleaned thoroughly), or insecticides

Processing, for example, excessive addition of preservatives in foods such as sausages, salamis, etc










https://www.niwa.co.nz/our-science/freshwater/tools/kaitiaki_tools/impacts/chemical-contaminates