Extreme weather events associated with climate change (such as the drought currently affecting much of Mexico), population growth, and rapid urbanization jeopardize the availability, quantity, and quality of water to meet the basic consumption and hygiene needs of the population.
According to the drought monitor of Mexico's National Water Commission (Conagua), in March 2024, nearly 60% of Mexican territory experienced moderate, severe, extreme, or exceptional drought. The areas affected by the last two, most intense, degrees represented 26% of the country.
This situation, which has led several authorities to declare alerts due to an imminent water crisis, implies problems in the supply of this resource to Mexican households. These problems can endanger the health of affected populations, mainly the most vulnerable, such as minors. Research based on data from the 2021 and 2022 Continuous National Health and Nutrition Survey found that the prevalence of water insecurity in Mexican households was 16.3% in 2021 and 16.5% in 2022.
More than 6 million households in Mexico had difficulties related to the access, availability, and use of water.
The same study, which considered the sociodemographic characteristics of the populations involved, reported that in 2022, households located in the northern border region (Chihuahua, Coahuila, Nuevo León, and Tamaulipas) had the highest proportion of water insecurity at 24.9%. They were followed by residential areas located in the Mexico City/State of Mexico region, with 19.9% insecurity, while the Peninsula region (Campeche, Chiapas, Quintana Roo, Tabasco, and Yucatán) had the lowest proportion of households with water insecurity (8.6%).
The analysis found significant changes in the magnitude of water insecurity. In 2021, the region with the lowest proportion was the northern border, which increased by 18.9 percentage points between 2021 and 2022. In addition, in the first year studied, 15.2% of households in rural areas had water insecurity, and by 2022, the percentage had increased to 17.2%.
Effects on Hygiene
Based on these results, the study concluded that Mexico must have an intensive action plan, focused on addressing environmental deterioration, water scarcity, and contamination to ensure the water security of the population, an issue it considers a matter of national security.
"The still temporary scarcity of drinking water can temporarily increase the risk of acute diarrheal diseases even in urban areas with good health infrastructure and medical services," Abiel Homero Mascareñas de los Santos, MD, a professor and researcher of pediatric infectious diseases at the José Eleuterio González University Hospital of the Autonomous University of Nuevo León in Mexico, told the Medscape Spanish edition.
Mascareñas de los Santos, a specialist in bacterial and viral infections and member of the Mexican Academy of Pediatrics, pointed out that during periods of water scarcity, the probability of contamination may be higher due to decreased river flow or reduced treatment capacity. "This increases the risk of consuming contaminated water," he said.
The former president of the Latin American Society of Pediatric Infectious Diseases added that "water scarcity can hinder maintaining good personal hygiene, such as handwashing and proper food preparation, thus increasing the chances of transmission of acute diarrheal diseases."
To these risk factors, Mascareñas de los Santos added poor sanitation due to water scarcity, storage of water in unhygienic containers, as well as population concentrations. "In densely populated urban areas, overcrowding can increase during periods of scarcity, thus facilitating disease transmission between people."
Addressing Risk Factors
The World Health Organization estimates that around 1 million people die each year from diarrheal diseases contracted as a result of unclean water, inadequate sanitation, or poor hand hygiene. However, as stated in a report, most of these diseases are preventable, so if these risk factors are addressed, around 395,000 deaths of children younger than 5 years could be avoided each year.
According to the organization, drinking water contaminated with microbes from feces poses the greatest risk for toxicity. In 2022, at least 1.7 billion people in the world extracted water for their personal consumption from sources with such microorganisms. This can lead to the transmission of diarrheal diseases, cholera, dysentery, typhoid fever, and polio. An estimated 505,000 deaths occur each year from diarrheal diseases.
Likewise, the World Health Organization observes that although the main chemicals in this type of water that pose the greatest risk are arsenic, fluorides, and nitrates, new contaminants are also dangerous and must be constantly monitored. They include drugs, pesticides, perfluoroalkylated molecules, polyfluoroalkylated molecules, and microplastics.
In addition to being a transmission medium for infections, water contaminated with microorganisms such as Enterococcus faecalis and E faecium could be a source of genes for microbial resistance to antibiotics with the potential to be transmitted to other bacterial species, said Yolanda López Vidal, PhD, head of the Molecular Microbial Immunology Program at the Department of Microbiology and Parasitology of the Faculty of Medicine of the National Autonomous University of Mexico in Mexico City, Mexico.
"The presence of enterococci, which is often associated with fecal contamination (of water) from various sources, could also be a potential route for the transmission of multidrug-resistant bacteria among the community," she said. She previously led a study analyzing microbial strains obtained from hospital samples, groundwater, and treated water for agricultural use in Mexico City.
On the other hand, a study assessing the risk for enteric diseases among infants living in areas with insufficient water supply in Mexico City found that although underground deposits presented a high risk for contamination by fecal matter, endemic patterns of diarrhea observed among children were mainly associated with poor sanitary practices.
In this study, the investigators found that 1-year-old infants had the highest proportion of diarrhea during the dry season, especially those who noticed an unpleasant odor in the water or consumed vegetables washed without disinfectant. By contrast, they observed the lowest risk in individuals who had water supply at home throughout the day, a flushing toilet, as well as covered containers to store water.
One of the main limitations of the research is that the bacteriologic samples were taken before the water was treated with chlorine, so it does not directly reflect its quality, said Mascareñas de los Santos. A third of the children studied drank bottled water and only occasionally reported drinking tap water.
Despite such limitations, these studies, as well as the recent case of hydrocarbon contamination recorded in a well that supplies several neighborhoods in the Benito Juárez municipality in Mexico City, show the importance of monitoring and control systems that guarantee a supply of water in sufficient quantity and quality to meet the needs of the population and preserve their health.
To achieve these aims, Mascareñas de los Santos suggested developing informational campaigns to promote adequate hygiene and sanitation among the population, strengthening epidemiologic surveillance systems for early detection and monitoring of cases of acute diarrheal diseases (with mandatory reporting systems to identify outbreaks), and training health professionals and the community in general on the prevention and management of such diseases.
"At all levels of government, it is important to implement programs to improve and maintain drinking water supply systems to guarantee its quality and availability, as well as promote its adequate treatment in homes, especially in communities where it is not available through pipes," said Mascareñas de los Santos.
Mascareñas de los Santos and López Vidal declared having no relevant financial conflicts of interest.
This story was translated from the Medscape Spanish edition using several editorial tools, including AI, as part of the process. Human editors reviewed this content before publication.