Children who don’t drink tap water have more cavities, study finds

A new study has found that children in the United States who don’t drink tap water are more likely to have tooth decay but are more likely to have higher levels of lead in their blood.

Researchers from the University of North Carolina at Chapel Hill looked at data from a nationally representative sample of almost 16,000 children and adolescents between the ages of two and 19 years, finding that overall three per cent of children and youth had elevated blood lead levels and 49.8 per cent had tooth decay. 15 per cent of those surveyed said that they drank bottled water instead of tap water, which typically contains fluoride, known to harden tooth enamel and protect against cavity-formation, whereas bottled water does not.

“Elevated blood lead levels affect only a small minority of children, but the health consequences are profound and permanent,” said Anne E. Sanders of the Department of Dental Ecology at UNC and study co-author, in a press release. “On the other hand, tooth decay affects one in every two children, and its consequences, such as toothache, are immediate and costly to treat.”

Bottled water sales in the United States have risen since 2014 when news broke about lead contamination in the water supply in Flint, Michigan, a crisis caused by public mismanagement which forced residents to use bottled water for drinking and bathing. In 2016, bottled water sales surpassed sales for soda pop for the first time in the US.

In Canada, fluoridation of city water supplies has been a hot-button issue, with some municipalities choosing to forego the practice in recent years, one which was first put in place across the country the mid-20th century. Last year a study found that children in the city of Calgary, which had discontinued fluoridation in 2011, had higher levels of tooth decay than their peers in Edmonton, where fluoridation is still in place.

That news raised concerns among parents and health groups, including the Canadian Dental Association and Alberta Health, both of which have underlined their support for municipal fluoridation. “The best available scientific evidence supports fluoridation as a safe and effective public health measure to improve oral health and reduce dental caries,” says a report this year from Alberta Health.

In September, city councillors in Moncton, New Brunswick, voted against restoring fluoridation, which was discontinued in 2011, although city dentists as well as the province’s chief medical officer of health had pushed for reinstatement.

The new study adds further complexity to the issue, as parents and health officials in some locales are seemingly forced into a trade-off between tooth decay and lead exposure.

“Our study draws attention to a critical trade-off for parents: children who drink tap water are more likely to have elevated blood lead levels, yet children who avoid tap water are more likely to have tooth decay,” said study co-author Gary Slade, also of UNC’s Department of Dental Ecology. “Community water fluoridation benefits all people, irrespective of their income or ability to obtain routine dental care. Yet we jeopardize this public good when people have any reason to believe their drinking water is unsafe.”

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