Now, a new study at Johns Hopkins University has pointed out that there are other interesting chemicals in the water - in fact, ironically, some of these substances may have been generated during water treatment.
In order to eliminate known toxic compounds, water treatment plants now commonly use oxidation methods to convert them into another potentially less harmful chemical substance called "transformation product". Although early studies focused on by-products such as chlorination and other water treatment processes, little is known about products formed in some of the more recent processes, such as hydrogen peroxide oxidation and ultraviolet light, and this is especially relevant to the reuse of water. Related.
"In general, we believe that these conversion products are less toxic, but our research shows that this may not always be the case." The study's lead author, Johns Hopkins Vuitton School of Engineering Environmental Health and Engineering The department’s Professor Carsten Prasse of the Bloomberg School of Public Health said: “Our results emphasize that this is only half the time. When we consider the quality of treated water, conversion products may Plays a very important role."
Prasse and colleagues at the University of California, Berkeley, studied phenolic organic chemicals, the most common class of organic chemicals in water supplies, because they exist in dyes, personal care products, pesticides, and natural products. Chemicals that exist in water.
In order to determine the changes in the phenolic compounds during the course of treatment, the team first used peroxide radicals to oxidize phenols, a process commonly used by water treatment plants. The results of this study have been published in the Journal of the National Academy of Sciences. Next, they borrowed a clever way from biomedicine: they added amino acids and proteins to the mix. Depending on what chemical reactions occurred, Prasser and his team could do some reverse calculations to determine which phenolic compounds must have changed in the previous step.
They discovered that the conversion of phenols into products including 2-butene-1,4-diol, a compound known to have negative effects on human cells, includes human cells including DNA damage. Interestingly, furan is a toxic compound in cigarette smoke and automobile exhaust and is also converted to 2-butene-1,4-diol, and this conversion may be responsible for its toxicity.
To more fully test the specific effects of 2-butene-1,4-diol on biological processes, the team exposed the compound to mouse liver proteins. They found that it affected 37 different protein targets that involved a range of biological processes, from energy metabolism to the synthesis of proteins and steroids.
An enzyme bound by 2-butene-1,4-diol plays a key role in apoptosis or "cell suicide". Inhibition of this compound in living organisms may result in uncontrolled cells. Proliferation or cancer growth. Other compounds that interfere with 2-butene-1,4-diol play a key role in metabolism. "There are many potential health consequences, such as obesity and diabetes," Prasse said. "There is a known link between insecticide exposure and obesity. Research like ours may help explain why this is so."
The results are exciting because this is the first time these methods have been applied to water treatment, Prasse said. Over time, they may be expanded to screen for other types of compounds than phenols.
Water purification is very challenging because pollutants come from many different sources - bacteria, plants, agriculture, waste water. In this process, it is not always clear what has been generated. "We are very good at developing ways to remove chemicals," Prasse said. “Once the chemical disappears, the work is done. But in fact, we don't always know what it means to remove this chemical: Is it going to be something else? Is this transformation product harmful?”
Prasse and his team point out that by 2050, it is estimated that two-thirds of the global population will live in areas that rely on drinking water. Drinking water contains runoff from farms and wastewater from cities and factories. Therefore, safe and effective purification methods will become more important in the coming years.
"The next step is to study how to apply this method to more complex samples and to study other contaminants that may lead to the formation of similar reaction conversion products," Prasse said. “Here we studied phenols. However, we use household products containing about 80,000 different chemicals, many of which will eventually enter the wastewater. We need to be able to screen multiple chemicals at the same time. This is a bigger goal. ."