A critical factor in any presidential primary election decision is evaluating which candidate among those seeking a party's nomination has the best chance of winning the general election in November. That's one reason - among many - that I voted for Barack Obama.

Just in case the Bush Administration hasn't generated enough reasons for you to care deeply about which party controls the White House - outrageous signing statements, executive branch power grabs, frightening Supreme Court nominations, writ of habeas corpus suspension, warrantless wiretapping, winking at torture, hundreds of lies leading to war in Iraq - the federal Food and Drug Administration just elucidated another, this one intensely local: perchlorate.

Confused? Bear with me.

The president appoints the heads of federal agencies like the Environmental Protection Agency and the FDA and sets the tone and direction for these and all federal agencies. 

Under George W. Bush, the EPA's tone and direction regarding perchlorate contamination is delay, defer and dither. 

The EPA explains that perchlorate is "both a naturally occurring and man-made chemical. Most of the perchlorate manufactured in the United States is used as the primary ingredient of solid rocket propellant. Wastes from the manufacture and improper disposal of perchlorate-containing chemicals are increasingly being discovered in soil and water."

The defense industry could be on the hook for staggering cleanup costs should the EPA adopt perchlorate standards similar to California's.

Perchlorate is also used in the manufacture of road flares (such as at Olin Corp.'s now-closed Morgan Hill plant, the source of South County's perchlorate plume), air bags, fireworks and explosives.

Perchlorate interferes with thyroid function. It's particularly dangerous for the development of the central nervous systems of fetuses and infants. Perchlorate contamination has been found in at least 25 states.

After seven years, when the EPA finally set a guideline (called a reference dose) addressing how much perchlorate adults can safely ingest, it chose one - 0.7 micrograms per day per kilogram of body weight - that was almost 25 times higher than expected, drawing lots of criticism.

Also, the EPA's reference dose translates to 24.5 parts per billion in drinking water, more than four times higher than California's standard of 6 ppb.

What's the relevance to the White House? Defense industry-related political action committees gave Bush roughly double the donations they gave to John Kerry, according to a World Policy Institute report that also noted, "Of the more than $13 million in arms industry contributions in the 2004 election cycle, 62 percent went to Republican candidates or committees, while 38 percent went to Democratic candidates or committees."

Are these slow and controversial decisions about an issue that could cause financial damage to those who gave so much to put Bush and his fellow Republicans in office any surprise? Hardly.

Last week, the FDA issued a report titled "US Food and Drug Administration's Total Diet Study: Dietary intake of perchlorate and iodine" that found detectable levels of perchlorate in 59 percent of more than 1,000 food samples tested.

The researchers tested samples from retail purchases of "foods representative of the 'total diet' of the average US population, which includes baby food, beverages including bottled water, dairy, eggs, fat, oil, fruits, grains, legumes, mixtures, meat, poultry, fish, sweets, and vegetables."

You might recall a 2004 study that found perchlorate contaminating 94 percent of milk and lettuce samples purchased in 15 states.

This study confirms that work and goes further: "It could be assumed that perchlorate would be found mainly in foods with high moisture content (e.g., milk and vegetables) because of its affinity for water, but results ... appear to indicate that perchlorate is more widely distributed in the food supply."

Nonprofit watchdog organization Environmental Working Group analyzed the FDA study and concluded that "every proposed or final drinking water standard fails to protect two-year-olds from routine, daily, unsafe exposure to perchlorate when combined food and water exposures are considered."

Do you want an EPA that will set reasonable perchlorate standards in a timely manner? 

I do. I believe a Democrat is more likely than a Republican to make that happen, and I believe that Barack Obama is the Democrat's best hope to win the White House.

Your vote in next week's primary election and in November's general election could have a direct impact on this important local matter.

Think about it before you vote on Super Tuesday.

Lisa Pampuch Lisa Pampuch is a technical editor and a member of the newspaper's editorial board. She lives in Morgan Hill with her husband and two children. You can reach her at lisapampuch@iname.com