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Some of Coca-Cola’s popular bottled water brand Dasani contains elevated levels of potentially dangerous chemical disinfectant byproducts, according to records obtained by Consumer Reports.
Tests of Dasani water packaged in half-liter bottles at a Florida plant in 2018 revealed levels of total trihalomethanes (TTHMs) that exceed a limit set by the state of California as well as a bottled water industry trade group, records show. TTHMs are produced when chlorination chemicals combine with organic matter in water. Some of the compounds are classified as potential carcinogens, and studies have linked them to liver and reproductive issues.
A Coca-Cola subsidiary submitted the Florida test report to New York regulators last year as part of the state’s annual permit process for bottled water manufacturers. Coca-Cola currently possesses active permits for several affiliated companies, according to the state health department website, including the Florida subsidiary. Consumer Reports obtained the records this week in response to a public records request filed with the New York health department, which regulates bottled water in the state and certifies more than 200 bottlers annually.
The records underscore the occasional inconsistency of bottled water regulations in the U.S. The test of Dasani at the company’s Jacksonville plant in 2018 registered 12 parts per billion (ppb) of TTHMs, records show. That met New York’s limit for TTHMs in bottled water of 80 ppb, also the federal standard set by the Food and Drug Administration, which regulates bottled water in the U.S. (The federal limit in tap water is 80 ppb.)
But the state of California’s standard for TTHMs in bottled water is more stringent, at 10 ppb. That’s also the limit set by the International Bottled Water Association, an industry trade group, for its members, including Nestlé and Cott Bottling. (Coca-Cola is not part of the group.) The IBWA has said it implemented the stronger TTHMs standard to “ensure the highest degree of public safety.”
Coca-Cola is licensed to distribute Dasani made at the Jacksonville plant to 13 states, according to the records, but it’s unclear if the company ships it across the U.S. to California. A spokesperson for California’s bottled water regulator didn’t have a comment for CR at press time. Not all Dasani had this level of TTHMs, either; records for other Coca-Cola plants licensed to sell in New York showed levels below 0.5 ppb.
A spokesperson for Coca-Cola didn’t respond to a request for comment at press time.
The records also highlight a pitfall in the voluntary system deployed by the industry to inform consumers about the quality of their favorite bottled water brand. Unlike tap water, there’s generally no requirement for bottlers to publish information on the quality of their brands, leaving consumers to voluntarily contact them for test results.
Some brands, like Dasani, post reports on their websites. The most recent Dasani report published online, however, is labeled as an “example” that reflects a “typical” analysis conducted of the water brand’s quality. For TTHMs, the example report shows non-detectable amounts of the compounds.
“Bottled water companies often do not disclose information about contaminants in their products—and this specific example is an illustration of that lack of transparency,” says Olga Naidenko, Ph.D., vice president of science investigations at the Environmental Working Group (EWG), a nonprofit advocacy and research group that published a study on bottled water in 2008.
The Unintended Consequence
Chlorination has long been heralded for its impact on the safety of drinking water. But the massive public health benefits it provided by dramatically reducing waterborne diseases also brought about an unintended consequence: disinfectant byproducts. In particular, four primary trihalomethanes—including chloroform and bromodichloromethane—created during the treatment process have been identifided by researchers as potentially dangerous.
“It is kind of ironic that the act of treating water to make it safe actually introduces carcinogenic compounds into the water,” says Jeff Cunninghaman, Ph.D, an associate professor in the University of South Florida’s Department of Civil & Environmental Engineering who researches water treatment and contamination. “However, overall, it is a good strategy: even though we introduce a low risk of getting cancer, we greatly decrease the risk of serious, acute disease from microbial pathogens, like cholera or typhoid fever.”
The Environmental Protection Agency, which regulates tap water in the U.S., had a 100 ppb limit on the sum of TTHMs, before lowering it to 80 ppb in the early 2000s. (The FDA followed suit, and implemented an 80 ppb limit for bottled water shortly thereafter.)
The EPA notes that limits are set based on what’s “feasible” for water systems to achieve—not just what’s best for public health—and takes cost into consideration. California regulators previously estimated that corresponded to a risk of one cancer case in 10,000 people who were exposed to TTHMs for a lifetime. The state is currently proposing a voluntary Public Health Goal, the level at which adverse effects are not expected to occur from a lifetime of exposure, for each of the four trihalomethanes at levels of 0.5 ppb and below.
Indeed, trace amounts of TTHMs are present in tens of thousands of regulated public water systems, according to a 2015 analysis of federal data by the nonprofit Environmental Working Group. Nearly 800 water systems serving 1.7 million people that year violated the 80 ppb limit for TTHMs, the analysis shows.
But studies have found low amounts could evem present a potential health risk. For example, a meta-analysis of TTHM research published in 2011 by Occuptational and Environmental Medicine, found that men exposed to averaged TTHM levels above 5 ppb throughout their lifetime had a significantly increased risk of bladder cancer than those exposed to less than that 5 ppb. And a study published this month by EWG estimated that an additional 8,000 lifetime cancer cases could be due to disinfection byproducts in water.
EWG’s Naidenko says that consumers could be surprised to learn that some bottled water has contaminants found in tap water.
“The problem with bottled water comes from the fact that the FDA allows bottled water to contain contaminants,” she says, “generally at levels close to what’s allowed for drinking water.”
Industry Standard Stricter
TK why the ibwa implemented a stronger standard
What Consumers Can Do
Cunningham says the only way to eliminate the cancer risk from TTHMs is to reverse course and stop chlorinating our water. But then, he says, “We are back to a severe risk for cholera or other water-borne disease. So we are pretty much stuck with some risk from THMs, any time we disinfect the water.”
Cunningham didn’t find the 12 ppb level in some Dasani concerning, as it meets the federal standard of 80 ppb, but he says that consumers should be notified about the presence of TTHMs in bottled water.
“Many people buy bottled water because they believe (rightly or wrongly) that bottled water is ‘safer’ than tap water,” he says. “Therefore it seems that they should be notified of the presence of very low levels of carcinogens in the water.”
“There is no reason to panic,” he adds, “because the risk is quite low—but it isn’t zero, and I think consumers should be informed of that fact. Then they can decide if they still want to buy bottled water, or if tap water is acceptable to them.”
Consumers with concerns about water quality could review the annual water quality report for their local tap water supply. CR also recommends looking for brands who abide by the TTHM limits set by California and the industry.
“Consumers should buy from brands that affirm compliance with the 10 ppb standard,” says Michael Hansen, Ph.D, a senior scientist at CR, “such as brands that are part of the IBWA.”
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