Does Cyanide Represent a Threat to Your Drinking Water?

Many of us will have heard of cyanide in Hollywood thrillers and spy movies; it’s probably one of the most recognized chemical names amongst non scientists. Cyanide is a carbon nitrogen chemical unit, and it can combine with a large number of inorganic and organic compounds. One of the most common forms is hydrogen cyanide that is needed to make compounds for synthetic fibers, including nylon. There are other cyanides that are often used in agriculture as herbicides. When cyanide enters our water supply, it can represent a significant threat to human health, and this has been recognized by the EPA. Let’s examine this issue in more detail and evaluate the risks to our drinking water supplies.

EPA Cyanide Regulations:Does Cyanide Represent a Threat to Your Drinking Water?

The Safe Water Drinking Act was passed in 1974, and it requires the EPA to determine the safe levels of chemicals that are present in our drinking water to avoid health related issues. These levels are called Maximum Contaminant Level Goals (MCLG), they are not enforceable and based on the possibilities of exposure and health risks. The MCLG levels for cyanide have been set at 0.2 parts per million (ppm), the EPA believes that this level would avoid the health issues that we will look at below.

The MCLG has allowed the EPA to set their enforceable standard, the Maximum Contaminant Level (MCL). The MCLs are typically set very close to the MCLGs, these factors in the capabilities of public water systems to detect and remove contaminants using appropriate water treatments. In this case, the MCL is also set at 0.2ppm; the EPA believes that the current technology and resources could reasonably detect and remove cyanide if it enters drinking water supplies above this level.

The Health Effects of Cyanide Exposure:

When people are exposed to cyanide in drinking water at a level above the MCL, they can suffer health problems. The type of health issue and severity can vary a great deal, depending upon the length of the exposure period.

Short Term Exposure: When people are exposed to elevated levels of cyanide over a relatively short period of time, they can suffer from health effects, such as tremors, rapid breathing, and neurological effects.

Long Term Exposure: As one would expect, exposure to cyanide over a prolonged period of time has the potential to cause more serious health issues, such as excessive weight loss, damage to the nervous system and thyroid effects.

The Risks of Cyanide Exposure:

A great deal of cyanide is released into the environment every year. The MCLG and MCL of 0.2ppm set by the EPA are tested regularly, and if the levels exceed that level, the public must be informed. Also, if the level of cyanide does exceed 0.2ppm, the water supplier must take immediate steps to reduce the amount. The EPA recommends the use of reverse osmosis, chlorine treatment and ion exchange to remove cyanide from drinking water. Despite these measures, many people install their own water treatment systems to add an additional layer of protection against cyanide and other contaminants.

By Mark Williams (NicMar President Mark Williams holds degrees in Applied Science and Industrial Thermodynamics, along with Agricultural Mechanization and Systems Engineering from Ohio State University. He also holds the highest possible industry ranking, being WQA (Water Quality Association) LEVEL 6 Certified.)

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