Arsenic from community water fluoridation: quantifying the effect.
Community water fluoridation is a WHO recommended strategy to prevent dental carries. One debated concern is that hydrofluorosilicic acid, used to fluoridate water, contains arsenic and poses a health risk. This study was undertaken to determine if fluoridation contributes to arsenic in drinking water, to estimate the amount of additional arsenic associated with fluoridation, and compare this to the National Sanitation Foundation/American National Standards Institute (NSF/ANSI) standard and estimates from other researchers. Using surveillance data from Ontario drinking water systems, mixed effects linear regression was performed to examine the effect of fluoridation status on the difference in arsenic concentration between raw water and treated water samples. On average, drinking water treatment was found to reduce arsenic levels in water in both fluoridated and non-fluoridated systems by 0.2 μg/L. However, fluoridated systems were associated with an additional 0.078 μg/L (95% CI 0.021, 0.136) of arsenic in water when compared to non-fluoridated systems (P = 0.008) while controlling for raw water arsenic concentrations, types of treatment processes, and source water type. Our estimate is consistent with concentrations expected from other research and is less than 10% of the NSF/ANSI standard of 1 μg/L arsenic in water. This study provides further information to inform decision-making regarding community water fluoridation.
Public Health Ontario, 300-480 University Ave., Toronto, ON, Canada, M5G 1V2 E-mail: ray.copes@oahpp.ca.
Emily
E
Peterson
Public Health Ontario, 300-480 University Ave., Toronto, ON, Canada, M5G 1V2 E-mail: ray.copes@oahpp.ca; Dalla Lana School of Public Health, University of Toronto, 155 College St., 6th Floor, Toronto, ON, Canada, M5T 3M7.
Howard
H
Shapiro
Public Health Ontario, 300-480 University Ave., Toronto, ON, Canada, M5G 1V2 E-mail: ray.copes@oahpp.ca; Dalla Lana School of Public Health, University of Toronto, 155 College St., 6th Floor, Toronto, ON, Canada, M5T 3M7.
Ye
Y
Li
Public Health Ontario, 300-480 University Ave., Toronto, ON, Canada, M5G 1V2 E-mail: ray.copes@oahpp.ca; Ministry of the Environment and Climate Change, 40 St. Clair Ave. W., 2nd Floor, Toronto, ON, Canada, M4V 1L5.
John G
JG
Minnery
Public Health Ontario, 300-480 University Ave., Toronto, ON, Canada, M5G 1V2 E-mail: ray.copes@oahpp.ca; Dalla Lana School of Public Health, University of Toronto, 155 College St., 6th Floor, Toronto, ON, Canada, M5T 3M7.
Ray
R
Copes
D001151:Arsenic / Q000032:analysis*; D060766:Drinking Water / Q000032:analysis*; D004784:Environmental Monitoring; D005457:Fluoridation / Q000009:adverse effects*; D009864:Ontario; D014874:Water Pollutants, Chemical / Q000032:analysis*
D060766:Drinking Water; D014874:Water Pollutants, Chemical; D001151:Arsenic