Mayfield: "It's Bulls--t, Man."

Jeremy Mayfield broke his long silence yesterday, speaking to ESPN.com’s Marty Smith and vowing to fight NASCAR every step of the way to regain his career and reputation.

Mayfield said, “Every time there's an action (by NASCAR), there's going to be a reaction from here on out. I try to be nice. I try to be respectful to them. I try to do everything right. But I'm not getting drug through the mud no more."

He said believes NASCAR is trying to make an example of him, challenging NASCAR CEO Brian France’s assertion that other drivers have failed substance abuse tests this season, but been cleared after conversations with their doctors. He also questioned France’s assertion that there is a list of substances banned by NASCAR, saying, “Now there's a list -- an exhaustive list. Right? Where's it at? It's bull----, man, and somebody needs to stand up and see through this."

He denied delaying a Monday drug test by more than seven hours, calling the events of that day “a wild goose chase," and claiming he was given just 18 minutes to report to a NASCAR-approved lab to provide a urine sample. "It was a wild-goose chase and I got pissed off about it," he said. "I was like, 'I'm not doing this for nobody.' Why would I? I wasn't running or hiding from anybody, because I don't have to.”

“I'm just tired of it,” he said. “Mentally. Personally. I go try to find a sponsor, (and) nobody will talk to you. Try to find a ride, nobody will talk to you. So then what do I do? I'm not going to sit here anymore and get slammed by (NASCAR)."

NASCAR spokesman Ramsey Poston said Mayfield has nobody but himself to blame for his current situation, adding, "Whatever happened to personal responsibility? Jeremy Mayfield is the one who tested positive for methamphetamines. He's the one who violated the substance abuse policy, and he's the one that put the other competitors and fans at risk. The judge's order is quite clear: Mr. Mayfield will have to comply with whatever drug-testing requirements are imposed… on him, and continue to do so."

In a related story, Mayfield’s wife, Shana, said they are considering selling their race team after being unable to secure sponsorship. She said they do not have the cash to field a car themselves, and are "looking at all options,” including the sale of the team’s assets.

In an effort to increase the level of understanding of the process, Sirius Speedway has consulted with a number of medical professionals to determine what specific tests and procedures Mayfield is likely undergoing, and what they mean.

In cases like this, "witnessed samples" -- where the subject is observed urinating into the sample container -- are not unusual. In fact, they are the norm. While almost certainbly uncomfortable for the test subject, "witnessed samples" are not unusual in this type of case.

Acquisition of urine samples is not a sterile procedure, so it makes no difference where the sample is taken, so long as it is witnessed and all parties sign off on the sample as it is taken.

The experts say that NASCAR is now almost certainly conducting more comprehensive tests on Mayfield than their initial screening. In most cases, the preliminary drug screening tests only for three basic types of drugs. When a positive result is found, the next step is usually to administer a “Drugs of Abuse Screening” which searches for drug groups: amphetamines , cannaboids, cocaine, opiates, phenycylidine, ecstacy, LSD, club designer drugs, heroin, prescription drugs prescription drugs of abuse, anabolic steroids, etc. This test reveals specific drugs in the subject’s system -- and equally important – their levels of concentration.

NASCAR's chosen laboratory will almost certainly follow "chain of custody of evidence" with the urine sample obtained from Mayfield on Monday, documenting each step in the process and maintaining a chain of evidentiary possession to prove that his sample was not tampered with or contaminated in any way.

When Mayfield produced his latest sample, NASCAR (or its laboratory) almost certainly required him to provide complete, written documentation of any and all medications he is taking; complete with name, dosage and last time taken. Medications have what is called a "half-life" and medical professionals can look up any medication and determine -- according to its half-life -- the approximate duration of effect for that drug. When results are obtained from Mayfield's most recent screening -- likely in 3-4 days -- a toxicologist can review the concentration of each compound in his system and tell when it was ingested and how much was ingested.

Virtually every drug leaves a footprint in a person's system, revealing it’s specific chemical makeup. There are obviously variables in any test, but there are parameters and fail-safes built into the drug-screening process to deal with those variables. When there is a question surrounding the results of a specific test, the laboratory can simply obtain a new sample and re-test.