Another set of chlorine disinfectant byproduct (DBPs)
Haloacetic acids (HAAs) are formed, along with other Trihalomethanes (THMs) and chlorate, when chlorine is used as a disinfectant in water, which in turn reacts with organic waste products, which are continually being contributed to the water (e.g. by swimmers), to form chlorine disinfectant byproducts (DBPs). This is the exact primary sanitation process that takes place at your local swimming pool.
There are 9 known HAAs, Australia regulates the first 5 of these 9 in drinking water. These levels are compared to that of the World Health Organisation (WHO) suggested levels below:
|
Australia |
(WHO) |
Health risk |
|
|
1. Monochloroacetic acid (MCAA) |
<0.15ppm |
<0.02ppm |
Group 3 |
|
2. Dichloroacetic acid (DCAA) |
<0.1ppm |
<0.05ppm |
Group 2B |
|
3. Trichloroacdetic acid (TCAA) |
<0.1ppm |
<0.2ppm |
Group 2B |
|
4. Monobromoacetic acid (MBAA) |
<0.15ppm |
<0.2ppm |
Group 3 |
|
5. Dibromoacetic acid (DBAA) |
<0.1ppm |
<0.05ppm |
Group 2B |
| 6. Bromochloroacetic acid (BCAA) | – | – | Group 2B |
| 7. Bromodichloroacetic acid (BDCAA) | <0.1ppm | <0.5ppm | Group 3 |
| 8. Dibromochloroacetic acid (DBCAA) | – | – | Group 3 |
| 9. Tribromoacetic acid (TBAA) | – | – | Group 3 |
Below are the International Agency for Research on Cancer (IARC) category group explanations as per scientific studies conducted:
-The category Group 1 is labelled ‘Carcinogenic to humans.’
-The category Group 2A is labelled ‘Probably carcinogenic to humans.’
-The category Group 2B is labelled ‘Possibly carcinogenic to humans.’
-The category Group 3 is labeled ‘Not classifiable as to its carcinogenicity.’
As a result of prolonged exposure to the above HAAs, Increased incidences of tumors in several organs including the liver and kidney, as well as effects to the male sperm and its production were identified in the experimental studies conducted on both rats and mice.
“There are no epidemiological studies of TCA carcinogenicity in humans. Most of the human health data for chlorinated acetic acids concern components of complex mixtures of water disinfectant byproducts. These complex mixtures of disinfectant byproducts have been associated with increased potential for bladder, rectal, and colon cancer in humans [reviewed by Boorman et al. (1999); Mills et al. (1998)].”
Trihalomethanes (THMs) are also regulated in Australia in drinking water, with the limit being <0.25ppm.
A question I am left with is: Why are HAAs and THMs regulated in Australia for drinking water, however they’re NOT regulated in Australia for the commercial pool industry?
Written by John Morrison BSc
References:
- International Agency for Research on Cancer (IARC). List of classifications. 2019.
- Thermo Fisher Scientific- Haloacetic Acids Analysis.
- Source: 74th Annual Victorian Water Industry Engineers & Operators Conference Page No. 56Exhibition Centre – Bendigo, 6 to 8 September, 2011 IMPACT OF WATER QUALITY AND TREATMENT ON DISINFECTION BYPRODUCT FORMATION Paper Presented by:David Cook Authors: David Cook,Senior Research Officer-Water Treatment,Mary Drikas,Research Leader – WaterTreatment, Australian Water Quality Centre
- Ref: tmp/Trichloroacetic acid (TCA) CASRN 76-03-9 IRIS US EPA.htm.
- https://cfpub.epa.gov/ncea/iris/iris_documents/documents/subst/0655_summary.pdf
- Guidelines for Canadian Drinking Water Quality: Guideline Technical Document – Haloacetic Acids.
- Australian Drinking Water Guidelines – National Health and Medical Research Centre.
- NTP TECHNICAL REPORT ON THE TOXICOLOGY AND CARCINOGENESIS STUDIES OF BROMODICHLOROMETHANE (CAS NO. 75-27-4) IN MALE F344/N RATS AND FEMALE B6C3F1 MICE (DRINKING WATER STUDIES) NATIONAL TOXICOLOGY PROGRAM P.O. Box 12233 Research Triangle Park, NC 27709 February 2006. NTP TR 532 NIH Publication No. 06-4468. National Institutes of Health Public Health Service. U.S. DEPARTMENT OF HEALTH AND HUMAN SERVICES.
- Potential Health Effects From Long Term Exposure Above MCL Liver, kidney or central nervous system problems; increased risk of cancer
- Monochloroacetic Acid in Drinking-water. World Health Organisation. 2004.
- Water Quality Glossary. South East Water Corporation. 2019.
