Sources of perchlorate
Perchlorate is a chemical that occurs naturally, although it may as well be man-made. In addition, perchlorate can also be found in some fertilizers and in bleach. It has found wide application in the manufacture of fireworks, flares, rocket fuel, and explosives1. Many of the sites where perchlorate can be found occurring naturally are, by and large, limited to the arid areas. Such deposits are largely low concentration.
On the other hand, man-made sources of perchlorate are mainly highly concentrated in comparison with the natural sources. Sites with high levels of perchlorate contamination are mainly involved in the production, testing, and disposal of perchlorate compounds and solid rocket propellants. Others include industrial production sites that use perchlorate compounds as reagents2.
EPA response for regulating and remediation
The Safe Drinking Water Act gives the EPA the mandate to regulate perchlorate. Peer review reports by various public health experts and independent scientists as well have played a key role in influencing the decision y the EPA to impose a regulation on perchlorate. The new decision by the EPA would be a reversal of the 2008 preliminary determination3. It takes into account the over 39,000 comments from members of the public regarding multiple public notices on perchlorate3.
This action is an attempt to create awareness among interested parties on the decision reached by the EPA on regulating perchlorate. Nonetheless, the action does not in any way try to impose any public water systems (PWS) requirements4. On the other hand, this action has laid the framework for the designing and the development of a primary drinking water regulation at the national level (NPDWR).
Following the finalization of the NPDWR, a number of PWSs could be forced to make an effort to abide by the requirements in line with the program required by the regulation5. In addition, the EPA also intends to create a drinking water standard that will take care of about 16 toxic chemicals that have been noted to pose a danger top human health.
The aim of the EPA is to continue assessing the health effects of perchlorate, along with the science behind their occurrence in public water systems. Moreover, the EPA intends to embark on a project aimed at examining the affordability and feasibility of treatment technologies aimed at removing perchlorate. The agency shall also assess the benefits and costs of potential standards.
Risk potential
Sufficient doses of perchlorate can interfere with the normal operations of the thyroid gland. Perchlorate disrupts the transportation of iodide into the thyroid gland, in effect reducing iodide availability that is necessary for the manufacture of thyroid hormones. These hormones are vital for normal growth, metabolism and development.
Pregnant women are especially at a greater risk of thyroid hormone synthesis disruption2. Others include the developing fetuses, newly-born infants, young children, and also person with low thyroid hormones levels (Massachusetts Department of Environmental Protection).
On the basis of such a potential concern, the EPA has deemed it necessary to propose a formal rule. The process shall entail the reception of feedback from important stakeholders in addition to the provision of any formal rule to members of the public via a comment process 3.
It is important to note that exposure to sufficient doses of perchlorate may result in adverse health effects similar to those brought about by iodine deficiency among humans. When there is not enough intake of iodine in the diet, the individual in question suffers from a decline in the synthesis and secretion of thyroid hormone.
Based on the severity of such an iodine deficiency, the individual in question can manifest such effects as impairment in behavior, speech, vision, movement, physical development, hearing, and intelligence4. Scientists also contend that sufficient doses of perchlorate can interfere with the ability of the thyroid gland to synthesize hormones vital for the development of both fetuses and infants1.
Monitoring data reveals that over 4 percent of public water systems contain detectable levels of perchlorate. In addition, the same data indicates that between 5 and 17 million individuals are at risk of drinking water containing sufficient levels of perchlorate.
Standards set by states such as California and Massachusetts
In Massachusetts, the MassDEP is in the process of commissioning a drinking water standard. The new standard will ensure that the maximum contaminant level of perchlorate in drinking water does not exceed 2 ppb3. It is important to appreciate that the new promulgation shall be the first veer drinking water standards in the country for perchlorate.
Furthermore, the Massachusetts Contingency Plan is also in the process of establishing perchlorate groundwater and soil standards to facilitate the cleaning up exercise of hazardous waste sites. Also, MassDEP plans to adopt a reference dose to facilitate risk assessment at specific sites. The state of California also regulates perchlorate as a contaminant in drinking water1. In this case, 6 micrograms per liter is the recommended maximum contaminant level of perchlorate in the state of California.
References
1. California Department of Toxic Substances Control, “Perchlorate ”. Web.
2. Isa, Jalil, “EPA To Develop Regulation for Perchlorate and Toxic Chemicals in Drinking Water.” Environmental Protection Agency. Web.
3. Massachusetts Department of Environmental Protection. “ Frequently Asked Questions: Perchlorate”. Web.
4. Trumpolt, Clayton et al. “Perchlorate: Sources, Uses, and Occurrences in the Environment.”Wiley Periodicals. Web.
5. United States Environmental Protection Agency. “Perchlorate”. Web.
Bibliography
California Department of Toxic Substances Control. “Perchlorate. “ California Department of Toxic Substances Control.
Isa, Jalil. “EPA To Develop Regulation for Perchlorate and Toxic Chemicals in Drinking Water.” Environmental Protection Agency.
Massachusetts Department of Environmental Protection. “Frequently Asked Questions: Perchlorate”. Massachusetts Department of Environmental Protection.
Trumpolt, Clayton et al. “Perchlorate: Sources, Uses, and Occurrences in the Environment.”Wiley Periodicals.
United States Environmental Protection Agency. “Perchlorate.” United States Environmental Protection Agency.