PORTSMOUTH — Efforts to reduce fluoride levels in the city’s drinking water will headline a busy agenda for the City Council tonight.

Included on the slate of items to go before the council beginning at 7 p.m. at City Hall is a motion to follow recent recommendations from the state Department of Health and Human Services, calling for cities and towns to adjust fluoride levels in their water supply.

The DHHS recommendation comes not long after the U.S. Department of Health and Human Services, along with the U.S. Environmental Protection Agency, released a study on the effects that over-fluoridation can have on humans.

The report, conducted under the auspices of the Centers for Disease Control and Prevention, found two in five children in America show signs of fluoride poisoning, and recommended reducing fluoride to 0.7 milligrams per liter from the previous recommended upper limit of 1.2 milligrams per liter.

Recommendations of the study are still in the comment period.

The current state-recommended levels range from .9 to 1.7 milligrams per liter. The city’s water supply systems have included fluoride at an average dosage of 1.0 milligrams per liter since 1973, when the city voted to begin the practice of adding fluoride.

Based on the recent report from federal regulators, the state DHHS announced support for cities and municipalities to lower the recommended level of .7 milligrams per liter in the interim period between now and publication of the final guidance and rule making.

According to a memorandum from City Manager John Bohenko, it would take the city one to two days to get all of the water-feed systems adjusted to a new dosage.

The subject of fluoride in the public water supply has become heated in Portsmouth since November, when resident Rick Horowitz brought his concerns to council members. Despite failing to gain the backing of the entire council on his fight to make Portsmouth “fluoride-free,” Horowitz recently told the Herald he felt vindicated when federal regulators released their study.

At the state level, a pair of legislators recently submitted a bill that would require municipalities to send notice to residents about the fluoridation of their drinking water. The proposed bill is currently being discussed in the House…

The meeting will be held in the Eileen Dondero Foley Council Chambers and will be televised live on Channel 22.