Opening a faucet in Botswana and drinking the treated water for consumption does not guarantee health. A study by the Barcelona Institute for Global Health (ISGlobal) shows that its regulations in this country allow concentrations of trihalomethanes – a chemical by-product resulting from the interaction of chlorine disinfectants with organic matter – 10 times higher than the European Union (100 micrograms per litre), in line with World Health Organization recommendations.
Research published in the journal Water Research reveals a “large gap” between high- and low-income countries in the way they regulate and control the presence of chemical contaminants in drinking water, the authors said. And they warn that prolonged exposure to trihalomethanes “is consistently associated with bladder cancer.”
“We have found that there is a lack of regulation in many countries; and there are those who have it but don’t do checks,” explains Cristina Villanueva, an ISGlobal researcher who participated in the study. According to analyzed data from 116 countries, 27 have no regulations regarding the presence of trihalomethanes in drinking water. And among the 89 countries that have ordinances, the maximum levels range from 25 micrograms per liter in Denmark to 1,000 in Botswana. Among these areas, the most restrictive countries are Austria, Zambia and Italy – whose guidelines set a maximum of 30 micrograms per liter – compared to the most lax, namely Ecuador (500), Australia (250), Mexico and Colombia (200). . . .
A standard, regardless of the allowable concentration, also does not ensure that the authorities will monitor compliance. Only 47 countries carry out routine checks, the research team found, and not always on the water used by the majority of their populations. In 14 of them, including China, India, Russia and Nigeria, which bring together 40% of the world’s population, they collect data on the concentration of trihalomethanes in specific cities or demarcated areas, so their results are incomplete. In five – Albania, Nigeria, Uganda, Vietnam and Zambia – not even that. For a further 33 it is not possible to know whether they carry out any type of control or not, as there is no data on this.
It is better to chlorinate the water and prevent diarrhea than to avoid the chemical risk
Cristina Villanueva, ISGlobal researcher
The presence of trihalomethanes is a sign that it has been chlorinated, which the WHO says is essential to eliminate pathogens that cause diseases like diarrhea, the leading cause of infant mortality among children under five worldwide. More than half a million people die each year from this preventable and treatable disease.
“It’s better to chlorinate the water and prevent diarrhea than avoid the chemical risk.” Villanueva clarifies that his study does not question the use of chlorine as a disinfectant, but the lack of regulations and controls regarding the adverse effects that its use causes: the production of pollutants such as trihalomethanes in large quantities.
There is no one-size-fits-all solution to improving water quality, but those that do exist are complex and unattainable in disadvantaged economies. “Additional levels of treatment and other complex processes can be afforded by high-income countries. For the less developed, the options are limited,” explains Villanueva. “Some choose to use disinfectants other than chlorine, such as Italy, or to reduce organic matter in the water before treating it,” says the expert. It also reduces the risk of trihalomethanes being generated by taking groundwater that is clean enough and contains less organic matter to interact with chlorine. “But it’s not always available.”
In developing countries, Villanueva suggests “looking for other tailor-made solutions”, such as treatment at the point of consumption, the use of ceramic filters or solar systems. ‘The lack of data in these countries is largely due to the fact that there is no centralized water supply and consumption is too fragmented, making control tasks difficult,’ he says.
The sixth of the 17 Sustainable Development Goals calls for ensuring universal access to safe, contamination-free water by 2030. According to the researchers, this justifies the need to deepen the study of the relevant legislation and its application. But there is still “a lack of knowledge about the presence of chemicals in drinking water, particularly in low- and middle-income countries,” they complain. The problem, they conclude, is growing; However, the care you receive is “limited” compared to the care you receive through extended care.
The authors acknowledge that water scarcity is a crisis that will only get worse. More than 2,000 million live in countries with water scarcity, a situation that has been exacerbated in some regions as a result of climate change and population growth, WHO notes. The same number of people use a drinking water source contaminated with feces, which this organization says poses “the greatest risk to drinking water safety.” According to them, in 2020, 74% of the world’s population (5.8 billion people) were using a safely managed supply of drinking water, available when needed and free from contaminants. ISGlobal’s findings confirm that the unknown and uncontrolled presence of chemicals prevents us from definitively confirming this statement.
Follow PLANETA FUTURO on TwitterFacebook and Instagram and subscribe to our “Newsletter” here.