Re: Fw: Google Alert - iodine -- meth, perchlorate levels

[Guest guest]

This second article is very interesting, discussing how perchlorate

standards are set. It mentions that people low in iodine are more

vulnerable to perchlorate than others, in terms of thyroid function.

Sharon

> Variable factors determine 'safe' toxin levels

> Inland Valley Daily Bulletin - Ontario,CA,USA

> ... Pirkle. He said women with low urinary iodine levels or

low levels of iodine in their diet are particularly

vulnerable. " This ...

>

Variable factors determine 'safe' toxin levels

By Pesick, Staff Writer

Inland Valley Daily Bulletin

Article Launched:12/31/2006 12:00:00 AM PST

How much of a dangerous chemical is safe to drink?

The answer to that question is something two states - California and

Massachusetts - don't agree upon. A new study by Centers for Disease

Control and Prevention scientists has put California on the defense

for its reliance on an older, smaller-scale study.

The dangerous chemical in question is perchlorate, which has been

found in drinking water wells throughout the Inland Empire, leading

Rialto and Colton to file federal lawsuits against a number of

corporations and government entities, including Goodrich, Black &

Decker, San Bernardino County and, in Rialto's case, the Defense

Department.

Also, the state has detected the chemical in groundwater both on and

off the Wyle site in Norco.

Used in the production of products such as rocket fuel, explosives

and fireworks, perchlorate can harm humans by interfering with the

functioning of the thyroid gland.

In July, Massachusetts capped the amount of perchlorate allowed in

drinking water at two parts per billion.

California, on the other hand, is heading toward adopting a standard

of six parts per billion. That won't become official until the state

Department of Health Services responds to comments it received on the

plan, which could take until the end of January.

The differences boil down to science and politics, officials and

environmentalists say.

Study's scope contested

This summer, before the release of the CDC study, the state Health

Services Department proposed six parts per billion as the maximum

level of perchlorate allowed in drinking water.

Some environmentalists complained that the level was too high, noting

it was three times higher than the level set by Massachusetts only a

month earlier.

State officials based their proposal on a study authored by the late

Dr. Monte Greer, who reported that healthy adults could safely be

exposed to perchlorate at concentrations of about 200 parts per

billion.

" We felt that the Greer study was really the best study to use, "

Allan Hirsch, a spokesman for California's Office of Environmental

Health Hazard Assessment, said before the CDC released its study.

The Greer study, however, was limited in scope. It exposed a

relatively small number of healthy adults - 37 - to perchlorate for

just 14 days.

Because of those limitations, Sharp, an analyst at the

Environmental Working Group, a nonprofit environmental research

organization, said California should have considered how perchlorate

can affect sensitive populations, such as children and people with

thyroid conditions.

And Massachusetts officials agreed.

Carol Rowan West, director of the Massachusetts Department of

Environmental Protection's Office of Research and Standards, put less

confidence in the Greer study than her counterparts in California.

" We had more concerns about the quality of the data and lack of data

on certain issues, " she said.

In addition, while California officials assumed that 60 percent of

the perchlorate a person ingests comes from drinking water,

Massachusetts officials put that number at 20 percent, saying people

consume more perchlorate from food.

CDC study and the thyroid

The CDC study provides policy makers with a great deal of new

information to chew on.

" It's a very respectable study from a highly respected organization, "

said Mayer, the regional perchlorate coordinator for the

Environmental Protection Agency.

The nationwide study found that even low levels of perchlorate can

affect thyorid hormone levels.

" We didn't expect to see such low levels of perchlorate have this

effect on the thyroid, " said one of the study's co-authors,

Pirkle.

He said women with low urinary iodine levels or low levels of iodine

in their diet are particularly vulnerable.

" This is going to be important information for those people who are

setting acceptable levels (for perchlorate), " he said.

California's state Office of Environmental Health Hazard Assessment

is now analyzing the CDC's data, Hirsch said.

Riley, the deputy director for Prevention Services at the

Department of Health Services, said the department is not legally

permitted to set a lower standard than OEHHA recommends.

Money and politics

Environmentalists also claim that political and cost considerations

help explain why California is moving toward a higher standard than

the one adopted by Massachusetts.

If the California standard were set at two parts per billion, the

costs of treating water would be " astronomical, " said Fraser,

Colton's director of water and wastewater.

He said water standards are often based on factors other than public

health. Water in the Bay Area, for example, is only disinfected, not

filtered, he said, because of political pressure to lower water-

quality standards.

" It just shows you how the political process sometimes can impact the

adoption of drinking water standards, " he said.