Haloacetic Acids (HAAs) are chemical compounds that contain chlorine and bromine. Exposure to HAAs in drinking water has been associated with skin and eye irritation, as well as increased risk of cancer. Because all HAAs can create health issues in high doses, the EPA limit for HAAs in water is 60 parts per billion.
HAAs can be formed by the chlorination, ozonation, or chloramination of water, typically occurring as a result of the disinfection process of drinking water. Its formation is further promoted when the water if more acidic, when the water contains a high organic matter content, and/or when the water is generally warmer. Chlorine in the water reacts with organic matter and bromide in the water to produce various HAAs.
The five main haloacetic acids - known collectively as HAA5, are:
monochloroacetic acid (MCA)
dichloroacetic acid (DCA)
trichloroacetic acid (TCA)
monobromoacetic acid (MBA)
dibromoacetic acid (DBA)
HAA5 are more likely to be found at higher levels in water supplies with surface water sources such as rivers or reservoirs, because soil and rock act as filters to reduce organic matter found in groundwater. They are formed as disinfection byproducts (DBPs) when chlorine is added to kill bacteria and other pathogenic microorganisms.
Haloacetic acids in water - and particularly HAA5 in water - are quite dangerous, and can arguably be declared one of the more dangerous water disinfection byproducts. If your water contains the federal limit of haloacetic acids, your chance of developing cancer is 1 in 10,000; the longer you are exposed to the federal limit, the higher your chance of developing cancer. HAAs are also especially dangerous for pregnant women.
Although high levels of direct exposure to HAAs through your drinking water is unlikely, its occurrence can result in red and irritated skin and eyes, as well as difficulty breathing.
The most prominent of the haloacetic acids' health effects is an increased risk of cancer. The EPA reports that prolonged exposure to haloacetic acids in water suggest this increased vulnerability, although other studies suggest that HAA exposure in water - while showing an increase in the development of liver tumors and liver cancer - have thus far only occurred in animals. Despite this, enough of a connection exists that it remains important to avoid excessive levels of haloacetic acids in drinking water.
The next of the haloacetic acids' health effects is an increased risk of birth defects. Although extensive studies have not been conducted on links between HAA exposure and human birth defects, studies on rats have demonstrated poor fetal growth and higher incidences of malformed heart and kidneys when pregnant rats have been exposed to high doses of HAA.
The final of the main haloacetic acids health effects is severe irritation to the skin. Both short- and long-term exposure to high levels of HAA can cause inflammation, skin loss, and damage to the structural protein, collagen. In some cases of exposure, skin damage can last from 2 to 15 weeks.
People become exposed to HAA contamination in several ways. HAAs are easily absorbed after ingestion, typically through HAA-contaminated drinking water. HAAs are slightly absorbed through the skin, and do not vaporize into the air at bathing water temperatures. Therefore, HAAs are potential health hazards mainly from water that is used for drinking and cooking. HAAs are eliminated from the body completely one day to two weeks after ingestion, depending on the specific HAA.
Short-term effects are not likely due to HAA exposure. When concentrated, HAAs have irritant and corrosive properties to the skin and eyes. However, the concentrations that form from disinfection are extremely dilute. For example, the concentration of trichloroacetic acid (TCA) typically found in drinking water with elevated haloacetic acids is at least one million times weaker than the concentration of TCA used in products for cosmetic skin peels. Additionally, although called "acids," HAAs in water are at least partially in non-acidic states.
Dichloroacetic acid (DCA) has been used for many years in the treatment of some metabolic disorders at doses that are about 10,000 times higher than anyone would be exposed to in drinking water. Some effects seen in patients included drowsiness, metabolism changes - such as decreased fasting glucose and cholesterol, and mild toxic effects to the nervous system (tingling in fingers and toes). These effects subsided after DCA treatment ended. At high concentrations of haloacetic acids given to animals in studies, toxic effects have been identified in the liver, testes, pancreas, brain, and nervous system.
High concentrations of HAA in animal studies have demonstrated increased developmental effects, including heart and kidney malformations, and lower growth rates in newborns. There are mixed results from human studies of the developmental effects of disinfection byproducts (which include HAA5) exposure. Recent studies have not observed most of the developmental effects found in earlier studies, although some studies continue to find associations between increasing disinfection byproduct exposure and growth deficits in newborns (e.g., lower than normal birth weight).
The U.S. Environmental Protection Agency (EPA) considers dichloroacetic acid (DCA) and trichloroacetic acid (TCA) to be potential human carcinogens. Animal studies have demonstrated an increase in the incidence of liver cancer. In some human studies, exposure to DBPs, including HAA5, increased the incidence of bladder cancer. Human studies have yet to confirm that DCA or TCA exposure increases the risk of cancer, although - based on the animal data - at the current HAA5 regulatory level, the cancer risk is estimated to increase by about 1 in 60,000 for every 10 years of exposure.
Reducing disinfection byproducts (DBP) in water systems involves balancing the benefits of preventing acute disease outbreaks against the health risks from long-term DBP exposure. Chlorine and other disinfectants remain a valuable tool in treating harmful microbial contaminants in drinking water at the municipal level. As awareness and analysis of DBPs - including HAAs - increase, so must the risks and hazards of DBPs be weighed against the benefits of current methods of disinfection. Currently, the risks of HAA exposure - as well as exposure to other DBPs in drinking water - suggest the necessity of personal, Point-of-Use (POU) water filtration as an additional drinking water safety measure.
The use of POU water filtration is reinforced by a study published in August 2006, which found that total levels of HAAs in drinking water were not affected by storage or boiling, but that filtration was effective in decreasing levels.
Multipure's solid carbon block filters work as a haloacetic acids water filter, reducing their concentration through a combination of mechanisms including mechanical filtration, physisorption, chemisorption and catalysis. In addition to mitigating haloacetic acids' health effects by reducing their presence in drinking water, Multipure's carbon block also reduces the presence of other contaminants like asbestos, cysts, particulates, lead, mercury, PCBs, radon, toxaphene, and chlorine.
Multipure's Aqualuxe, Aquaperform, Aquaversa, and Aquamini drinking water systems are NSF-certified according to NSF/ANSI Standards 42 (Aesthetic Effects, e.g., chlorine and particulates), 53 (Health Effects, e.g., asbestos, lead, and HAAs), and 401 (Emerging Compounds/Incidental Contaminants, e.g., pharmaceuticals, pesticides, and herbicides) for the reduction of dozens of contaminants. NSF certification offers the assurance of third-party testing and verification that Multipure's products perform at the exceptional level claimed
If you are interested in a system to protect your drinking water from HAAs or other contaminants, please check out Multipure's Drinking Water Systems below or contact your local Multipure Independent Builder for more information.