A medical review reveals that high levels of some minerals and metals found within environmental water supplies could increase the risk of nontuberculous mycobacteria pulmonary infections in people with cystic fibrosis.
In particular, the presence of the metals molybdenum and vanadium along with sulfate—a collection of mineral salts—in the U.S. municipal water system carries an association with an increased incidence of mycobacterial pulmonary infections.
According to the researchers – from the U.S. National Institute of Allergy and Infectious Diseases – this represents a leading of drinking-water associated illness. This is based on certain environmental conditions, including the presence of trace metals, contributing to a higher abundance of the mycobacteria in the water: Mycobacterium avium complex (MAC) and M. abscessus.
MAC is a group of mycobacteria comprising M. intracellulare and M. avium; these organisms are commonly grouped because they infect humans together. The presenting features of MAC include chronic cough, weight loss, and fevers. M. abscessus is a common soil and water contaminant, responsible for both chronic lung infection and skin and soft tissue infection. Globally, the incidence of M. abscessus infections appears to be increasing over time.
Mycobacterial species are generally aerobic, non-motile, and capable of growing with minimal nutrients. they are hard to kill due to their ‘waxy’ cell membranes providing a barrier that is difficult to penetrate using many types of disinfectants.
These bacteria are linked to chronic lung infections in people with cystic fibrosis and other lung diseases. Cystic fibrosis causes the body to produce thick mucus, leading to lung damage and trapping bacteria.
The researchers measured whether the concentration of metals and minerals in the water to determine if this had any influence on the probability of MAC and M. abscessus infection in people with cystic fibrosis.
The data examined included the Cystic Fibrosis Foundation Patient Registry, a repository of data relating to 3,897 people with cystic fibrosis living in states that had trace metal water data available in at least 50 percent of counties: Arizona, California, Colorado, Connecticut, Maine, Massachusetts, Nevada, New Mexico, Rhode Island, Utah and Wyoming.
The study analysis showed that 484 people had MAC while 222 had M. abscessus infections. The presence of sulfate and vanadium was positively associated with MAC, and the presence of molybdenum was positively associated with M. abscessus.
The inference is that water-quality elements increase the risk of bacteria-related pulmonary infections. This is something that needs to be tested from further research. Should these findings be replicated, they will emphasise the importance of good quality water – of suitable drinking water standard – and the necessity to ensure that all homes and hospitals are supplied with water of suitable quality.
Chemical contaminants of drinking-water are generally afforded a lower priority than microbial contaminants, since the adverse health effects from chemical contaminants are more likely to be associated with long-term exposures (whereas the effects from microbial contaminants are usually immediate). This research shows that these considerations are not mutually exclusive.
The research appears in the journal Environmental Epidemiology, titled “The risk of pulmonary NTM infections and water-quality constituents among persons with cystic fibrosis in the United States, 2010-2019”.
