Tuesday, March 10, 2009

Wading into debate over arsenic risks — Many factors to consider in finding safe level of contaminant in area water supply

Editor’s note: This is a continuation of an examination of arsenic levels in drinking water. For last week’s story, on March 4.

By Jenny Neyman
Redoubt Reporter

When Susan Bulkow, the local Alaska Drinking Water Program coordinator with the state Department of Environmental Conservation, gets a phone call from a central Kenai Peninsula resident asking about arsenic in the water supply, the question is usually straightforward:

Should I be concerned?

Her answer isn’t straightforward. In most cases, there is no simple “Yes” or “No” to that question, because there are no simple answers to many questions regarding arsenic.

The best Bulkow can do is offer information, wade carefully into the debates that swirl around arsenic contamination, and let residents decide the answer for themselves.

Epidemic or not?
A few things are widely agreed upon when it comes to arsenic — it’s here, and it’s bad for you. It’s been linked to cancer, and can contribute to a slew of other health problems, including fatigue, skin damage and problems with the circulatory system. Some level of arsenic routinely shows up in water samples across the central peninsula, in city and private wells.

What does that mean for peninsula residents? Is arsenic an epidemic that warrants a run on bottled water and filtration systems, where every glass of tap water is a tumor waiting to happen?

Or is it less dramatic than that — more a cause for routine concern, like replacing smoke detector batteries and making sure the garage door is open when warming up the car?

It’s a difficult question to answer, because some of the information necessary to make the leap from “if this” to “then that” is missing.

The biggest hole is in records, as a result of regulation. The Environmental Protection Agency regulates and monitors arsenic levels in public water supplies — from cities and other municipalities — but there is no oversight of private wells. Banks require water quality tests on nitrates and coliform bacteria levels in private wells when homes are bought and sold, but no entity requires arsenic testing.

As a result, and since arsenic is undetectable by taste, sight and smell, many homeowners on private wells simply don’t know how much arsenic is in their water. And there are no comprehensive records of arsenic levels in private wells on the central Kenai Peninsula to accurately gauge how widespread contamination is.

There is anecdotal information available, but some points to arsenic being an epidemic problem, and some points the other direction.

Dr. Robert Thompson, with a practice in Soldotna, said he has recommended over 1,000 patients get hair mineral analysis done in the past five years, which in part measures the level of arsenic in their systems. He believes arsenic is a significant concern.

“It’s a huge problem on the peninsula. About 80 percent of the wells, based on the testing I’ve seen, have high arsenic levels,” Thompson said. “I’m more surprised when they’re not elevated than when I see them when they are elevated.”

Mike Polocz, who offers arsenic testing with Culligan Water, said he’s routinely found high levels of arsenic in private wells he’s tested —up to 70 parts per billion or more. He agrees with Thompson that high levels occur particularly in certain areas, including Sterling, along Kalifornsky Beach Road and near Sports, Longmere and Mackey lakes.

Mike Tauriainen, owner of Tauriainen Engineering and Testing, in Soldotna, which is certified to conduct water analysis and forwards water samples to Anchorage for arsenic testing, said arsenic isn’t a huge concern.

“It varies from nondetectible — below the detection limit, probably down under 1 part per billion, which is an incredibly small amount — to over 100 parts per billion. But that’s uncommon. We have seen a few samples come in at over a hundred,” he said.

Tauriainen estimated that 1 percent to 5 percent of the water samples he sees test high for arsenic.

“We are blessed with pretty good water on the peninsula, as far as health concerns go,” Tauriainen said. “My personal opinion is that it’s generally not a very significant factor, but some people are more sensitive to different minerals, including arsenic. At the allowable level of 10 parts per billion, I don’t think that there’s any significant cause for concern.”

He also said he hasn’t seen evidence of arsenic showing up in higher concentrations in some areas than others. Arsenic levels, and water quality in general, can vary by area, but well depth probably has more to do with arsenic than location, he said.

“We really haven’t done a study of it, but I haven’t really noticed that one particular area has more than others,” Tauriainen said.

“Typically, the deeper the well, the more likely it is to have arsenic, because water has been in residence longer with arsenic. But it’s not a hard and fast rule.”

A rising tide?
A misperception Bulkow has heard is the level of arsenic in the water supply is rising.

“I’m not aware of there being an increase associated with arsenic,” she said.
There has been a concern that earthquakes and seismic activity lead to an increase of arsenic in water, but that’s probably not the case, she said. Probably.

“It is possible that some earthquakes could loosen deposits, and you could temporarily see an increase. We don’t know. We haven’t actually done that kind of testing to substantiate those claims. We have had other people tell us that they believe there is a correlation,” Bulkow said.

Tauriainen said he doesn’t think the typical magnitude of earthquakes felt on the central peninsula cause long-term changes in water quality.

“We don’t have evidence of that. We have not done a study, but normally the levels will stay roughly the same,” he said.

Maybe if the central peninsula contained more bedrock, earthquakes might fracture the rock and introduce more arsenic-bearing sediments into underground aquifers. But central peninsula communities sit on 1,000 feet of unconsolidated sediments, Tauriainen said, which may shift around during earthquakes, but don’t crack or undergo a large amount of upheaval.

However, aquifers can and do change, and wells can go dry or produce more water, or bring up new sediments if pumped hard. All of which could potentially affect water quality.

“If you’ve never tested private wells for (water) quality, you should, and if you have tested it in the past, it doesn’t hurt to get tested again to make sure you’re comfortable with those test results,” Bulkow said.

She said the increased buzz about arsenic is more likely due to increased attention on arsenic than increasing arsenic levels. The increased attention has come because the Environmental Protection Agency lowered the limit of arsenic contamination allowed in public water sources.

The maximum contaminant level was lowered from 50 parts per billion to 10 parts per billion in 2006. The lower limit meant an increased number of water sources exceeded the allowed level of arsenic, but it doesn’t mean the amount of arsenic changed, Bulkow said. It’s just that 40 ppb was considered fine prior to 2006, and over the limit post 2006.

Reaching the limit
How much is too much is a basic question in determining a resident’s risk from arsenic, but debate swirls over what that level should be.

Prior to 2006, the EPA’s maximum contaminant level of 50 ppb was thought to be the difference between safe and not. And some people still think it is, even after the maximum contaminant level was lowered to 10 ppb.

“There’s a lot of conflicting data on arsenic. People believe the mcl is too high, and there are some that say the mcl is low,” Bulkow said.

“EPA is constantly looking at new research data that’s available to determine whether their current standards are consistent with what is being discovered in the lab and through reporting of discoveries and through the CDC (Centers for Disease Control and Prevention) and other agencies. If they look at the data and decided the mcls were set too high, they revisit them and lower them. That’s what they did with arsenic,” she said.

Opponents of the lower mcl level point out that many of the studies done on arsenic took place in Third World countries, where poverty, poor sanitation and other factors already contributed to compromised health, Bulkow said.

She also said the arsenic limit assumes a sole water source, which typically isn’t the case.

“The mcl is set on the idea people drink the same water source every day all your life — 2 liters a day out of the same source. Most people don’t drink all their water all their whole life from one source,” she said.

Arsenic exposure of 200 ppb is toxic to a human. But arsenic is bioaccumulative, meaning even low-level exposure over time can build up to the point where it impacts health. Having over 10 ppb arsenic in a person’s system can increase their cancer risk by 30 percent, Thompson said.

But people, just like their wells, are different. Some people are more susceptible to effects from arsenic than others, just as some may drink more water than others. Even among the heavy water drinkers, some get more from their home water source, while others drink it from work, bottled from the store or from other sources.

All those variables make it difficult to determine one standard limit that is theoretically safe for all, whether it’s 10 ppb, 50 ppb or somewhere in between.
“We have to set the level someplace, so EPA is saying 10 is the level you should be concerned about. We have to draw the line somewhere, and the lines move,” Bulkow said. “It’s always based on more evidence and study and EPA is trying to do the best we can to protect public health with data we have at the time.”

Rather than being concerned over where the limit is set, Bulkow recommends residents use the 10 ppb limit as a guideline for considering their own individual arsenic exposure risk and deciding what they should do about it.

“I think what they should be concerned about is whether they have arsenic in the water and whether it should be treated,” Bulkow said.

She said people should have their water tested by a certified lab, discuss those results with their physician and a water treatment professional and decide from there whether, and how extensively, they should filter their water.

“They can look at the overall exposure risks that they have and look at their treatment options. I don’t want people to overreact because they all of a sudden find out they have arsenic in their water. But nobody ever feels like they’re overreacting to public health risks. I just want people to take it into perspective,” Bulkow said.

In the absence of regulations extending to private water sources, individual choice comes to the fore.

“Between 10 and 50 parts per billion, according to the EPA, is a concern,” Tauriainen said. “I’m not sure that it is, but for some people it is a concern. If somebody isn’t sleeping well at night because they’re worried about their water, it’s worth putting some kind of treatment on it.”

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