샌 루이스 오비스포(San Luis Obispo)시가 이달 초 식수에서 트라이할로메테인(TTHM) 수치가 상승했다는 사실을 시민들에게 알렸다. 시민들은 안전성에 대해 우려하며 문제의 해결방법을 찾기 시작했다. 장기간에 걸친 높은 수치의 TTHM을 섭취하게 되면 암을 일으킬 가능성이 있다.

정수처리장 감독관 Dean Furukawa은 “식수가 안전하게 유지되고 있고 도시가 TTHM 수치를 80ppb이하로 떨어뜨리기 위한 조치를 취하고 있다”고 밝혔다. 그럼에도 불안해하는 시민들은 개인적으로 물검사를 진행했으나 개인의 사용 식수에 따라 TTHM의 농도가 다르기 때문에 검사 결과는 변동이 많았다.

시민들을 위해 시 관계자는 일부 탄소 필터 TTHM을 줄이는 데 도움이 될 수 있다고 설명했지만 다른 적절한 대안들을 제시하지는 못했다.

Concerned San Luis Obispo residents are taking matters into their own hands after the City notified people the drinking water has elevated levels of total trihalomethanes earlier this month.

“Our levels actually came back higher than what the notice said,” said Melissa Davis, who had her water tested.

The results showed elevated levels of total trihalomethanes (TTHM) in her tap water, at 91 parts per billion, and filtered water, at 97 ppb. The city tested water at Southwood Dr. and Johnson Ave sample site, and found 81.2 ppb. The EPA standard is 80 ppb.

Consumed at high levels and over an extended period of time, TTHM has the potential to cause cancer. The Environmental Working Group (EWG) also cites studies that show lower birth weights and developmental disorders for women in their third trimesters.

Davis, worried because she has a two-year-old son and is expecting another, contacted city officials for more answers.

“We felt the notice pertained to the general public, but what if you have little ones or you are expecting, or nursing does that make any difference at all” Davis said.

Water treatment plant supervisor Dean Furukawa maintains the water is safe to drink and the city is taking steps to get the levels back under 80 ppb. Davis says he recommended she speak with a doctor.

Dr. Rene Bravo says many parents have called since the city’s notice came out; however, he is not familiar with TTHM causing birth defects.

“The chronic health effects really revolve around increased incidents of cancer  liver, kidney, bladder cancers,” Dr. Bravo said. “Regardless of the report of contamination here, I would always advise for women who are pregnant to seek the cleanest possible water source, be it reverse osmosis or bottled water.”

San Luis Obispo County Public Health Officer Penny Borenstein says she has young children and “would have no hesitation now drinking the city’s tap water, even if I was pregnant, even if I had cancer.”

She says when you test your own water, the results can be off because concentrations of TTHM can fluctuate. Borenstein also says the limits are set on the conservative side.

“Usually the limits are very protective, especially in California. They cover all persons and so if there are any vulnerable populations, the threshold is set at a very low level,” Borenstein said.

Because the city isn’t planning on testing the water again until mid-August, many residents want peace of mind in the meantime.

“If we are concerned even a little bit, what are our options. If reverse osmosis filters don’t work, then what will” Davis said.

City officials have been hesitant to give alternatives, but say some carbon filters may help reduce TTHM.

The EWG calls TTHM “toxic trash” and recommends these filters: click here.

Researchers there say to look for National Sanitation Foundation (NSF)-approved filters.

[출처 = NSF International / 2015년 7월 16일]