Drinking Water Contaminants- Styrene
Styrene in Drinking Water: A Comprehensive Guide
What is Styrene and Its Uses?
Styrene, an oily organic liquid with a pleasant, aromatic, almost floral odor, serves as a crucial building block for various industrial applications. Initially, styrene was predominantly used in the synthetic rubber industry. However, its versatility has expanded its usage as a foundational compound for polymers, contributing to the production of plastics, resins, coatings, and paints. Common trade names and synonyms for styrene include vinyl benzene, phenethylene, cinnamene, Diarex HF 77, styrolene, styrol, styropol, and others.
Health Concerns and Regulation of Styrene
In 1974, the Safe Drinking Water Act was passed by Congress, mandating the Environmental Protection Agency (EPA) to establish safe levels for chemicals in drinking water that could pose health risks. The EPA sets non-enforceable levels known as Maximum Contaminant Level Goals (MCLGs) based on potential health risks and exposure. For styrene, the MCLG is set at 0.1 parts per million (ppm), aiming to prevent potential health issues.
Health Effects
Short-term Exposure: At levels above the MCL for short periods, styrene may cause nervous system effects such as depression, loss of concentration, weakness, fatigue, and nausea.
Long-term Exposure: Chronic exposure to styrene above the MCL may lead to liver and nerve tissue damage and potentially increase the risk of cancer.
Maximum Contaminant Level (MCL)
The EPA has established an enforceable standard called the Maximum Contaminant Level (MCL) for styrene, also set at 0.1 ppm. This level is determined based on the capabilities of public water systems to detect and remove contaminants using available treatment technologies.
National Primary Drinking Water Regulations
The National Primary Drinking Water Regulations encompass the drinking water standards and the regulatory framework ensuring these standards are met. All public water supplies must adhere to these regulations.
Styrene Production and Environmental Release
In 1993, the production of styrene reached 10.7 billion pounds. This chemical is released into the environment through emissions and effluents from its production and use in polymer manufacturing. Consumers may come into contact with styrene through resin products used in fiberglass boat construction and repair, auto body fillers, and polystyrene containers used for food products.
From 1987 to 1993, according to the EPA’s Toxic Chemical Release Inventory, styrene releases to land and water exceeded 2 million pounds, primarily from adhesives and sealants industries. Texas and Louisiana were the states with the highest releases.
Environmental Impact of Styrene
When released into the environment, styrene rapidly evaporates and is broken down by microbes. It does not readily bind to soils and has minimal potential to leach into groundwater due to its rapid breakdown. Styrene does not tend to accumulate in aquatic life.
Detection and Removal of Styrene from Drinking Water
Since 1992, regulations for styrene have been in effect. Between 1993 and 1995, the EPA required water suppliers to collect and analyze water samples every three months for one year to determine the presence of styrene above 0.5 ppb. If detected, continuous monitoring is required.
If styrene levels consistently exceed the MCL, water suppliers must implement measures to reduce its concentration. The EPA has approved the use of granular activated charcoal combined with Packed Tower Aeration as effective treatment methods.
How to Identify Styrene in Drinking Water
If styrene levels exceed the MCL of 0.1 ppm, the water system must notify the public through various media channels, including newspapers, radio, and TV. Additional actions, such as providing alternative drinking water supplies, may be necessary to mitigate public health risks.
Drinking Water Standards
- MCLG: 0.1 ppm
- MCL: 0.1 ppm
Styrene Releases to Water and Land, 1987 to 1993 (in pounds)
| Water | Land | TOTALS (in pounds) |
|---|---|---|
| 275,888 | 1,796,451 | 2,072,339 |
| Top Ten States* | ||
| TX | 160,411 | 572,294 |
| WV | 1,600 | 555,360 |
| IN | 0 | 124,794 |
| WI | 0 | 102,973 |
| OH | 0 | 90,358 |
| GA | 0 | 79,000 |
| LA | 53,430 | 0 |
| FL | 3,880 | 0 |
| NY | 32,332 | 0 |
| KY | 18,000 | 0 |
Major Industries Contributing to Styrene Releases
| Industry* | Water (in pounds) | Land (in pounds) |
|---|---|---|
| Adhesives, sealants | 537,360 | 53,736 |
| Concrete products | 398,424 | 39,842 |
| Synthetic rubber | 152,215 | 15,221 |
| Misc. plastic products | 515,201 | 51,520 |
| Plastics and resins | 25,133 | 7,136 |
| Boatbuilding, repair | 220,832 | 22,083 |
| Car parts, access. | 79,250 | 7,925 |
| Misc. Indust. organics | 34,275 | 3,428 |
| Travel trailers, campers | 45,129 | 4,513 |
| Custom plastic resins | 720 | 72 |
- Land totals only include facilities with releases greater than 1,000 pounds.
Conclusion
Understanding the presence and impact of styrene in drinking water is crucial for public health and environmental safety. The EPA’s regulations and guidelines ensure that water suppliers are equipped to detect and mitigate styrene levels, thereby safeguarding the health of communities across the United States.