Radioactivity, a phenomenon of the spontaneous emission of particles or waves from unstable atomic nuclei, has recently made news due to its increasing presence in water sources globally, causing growing health concerns. Three types of radioactive emissions exist: Alpha, Beta, and Gamma. The first being positively charged helium atoms, the second being negatively charged electrons, and the last, neutral electromagnetic radiations.
Key Naturally Occurring Radioactive Materials (NORM) series existing in the earth’s crust include uranium, thorium, and actinium. These are known to contaminate our water resources. Despite every water type containing a small degree of radiation, danger arises when these levels become extended, affecting human health. Radioactivity levels in drinking water can be evaluated using a gross alpha test and is measured in Becquerel (the SI unit) or in Curie. To quantify the amount of radiation absorbed by human tissue, the unit Sievert is used.
Sources of Radioactive Contamination in Water
Contamination in water can happen through various natural and anthropogenic (human-induced) sources. Natural sources include Radium, a radioactive element found in aquatic systems that can infiltrate groundwater through aquifer rock dissolution, decaying of uranium and thorium, or desorption processes. Notably, radium is a radionuclide formed through the decay of uranium and thorium in the environment. Magma can occasionally release radioactive gases into the environment and NORM percolation from soil sediments can cause groundwater contamination.
In terms of anthropogenic sources, atmospheric deposition of cosmogenic radionuclides, which are radioactive isotopes distributed within the Earth system and produced by natural processes, adds radioactive nuclei to surface water. Nuclear reactors and warhead experiments play a significant role in discharging human-induced radionuclides, and nuclear power plants situated in coastal areas contribute to marine water radioactive contaminants by releasing atomic waste. These power plants also utilize water as coolants, leading to further contamination.
Other contributing factors include the dumping of radioactive wastage from medical equipment like X-rays and MRIs, mining activities of radioactive elements like uranium, thorium, and nuclear accidents such as those in Colorado’s Rocky Flats plant, Fukushima, and Chernobyl.
Health Impacts of Radioactive Pollution
Exposure to radiation through polluted water and food can induce severe health repercussions, including acute radiation syndrome or dermal radiation injury due to absorbing high radiation doses. Radiation exposure is also linked with various physiological disorders like cancer, leukemia, genetic mutations, and cataracts. Notably, ionizing radiation can trigger mutations in germ cells, leading to structural alterations in DNA that can be passed on to offspring, causing premature death or serious mental illness.
How to Approach Radioactive Contamination in Water
Given the above, it is crucial to monitor radioactive pollutants and implement proper preventative measures to ensure the safety of water resources from both natural and anthropogenic sources. Known effective remedial measures for treating radioactive contaminated water include aeration, reverse osmosis, ion exchange, and granule carbon adsorption.