Which monitoring scheme most effectively balances the benefits of community water fluoridation and salt iodization while guarding against local increases in fluorosis and iodine excess?

• A. Rely exclusively on self-reported salt brand use in surveys to infer both fluoride and iodine exposure because laboratory measures are unnecessary and unreliable.
• B. Conduct yearly mass screenings for bone stiffness in all adults as the single most sensitive indicator of both fluoride and iodine overexposure, and ignore dental outcomes.
• C. Only monitor iodine in urine of adults because children and pregnant women are unaffected; fluoride need not be measured since cosmetic fluorosis is not a public-health concern.
• D. Regular measurement of fluoride in water supplies and dental fluorosis surveillance in children, combined with periodic population iodine status surveys and targeted education on supplement use in pregnancy.

Answer: (D)