Oh, the life of an environmental biologist. While collecting and culturing toxic material, sometimes the opportunity to play marriage counselor pops up like some exotic slime in a Technicolor Petri dish. Robert Veldman has played both roles while analyzing ugly stuff gathered from people''s Monterey Peninsula homes.

I met him in his role of mold expert.

I had never even thought of mold until recently, when my son, daughter, husband and I moved into a very damp house. Puzzling symptoms soon followed. One of us always seemed to have a scratchy throat or stuffy nose, and all of us started waking up with headaches.

We always felt better when we left the house.

But it wasn''t until I read "MOLD: A Health Alert" in USA WEEKEND magazine that the idea of dangerous mold grew on me. The article, describing a Texas family''s nightmare situation, was terrifying. The Texans'' dream house sprung a plumbing leak, allowing mold to spread to such an extent that the entire family--including the baby--developed permanent health problems, including scarred lungs and memory loss.

Were we facing a similar situation at our house?

Petrified, I called several companies until I was referred to Veldman, 28, operations manager at ATC, a Monterey environmental assessment company. He demands payment up front, because he''s been stiffed quite a few times.

Often one half of a married couple calls him for testing and the mate gets outraged. "I''ve had it about 50-50 with males and females not believing their spouse that the mold is making them sick," he says.

Veldman shakes his head. "When you call to give them the results, they don''t want the answers. I hear the husband say, ''She''s a hypochondriac,'' or the wife say, ''He''s nuts.'' One lady told me she was afraid to call me because of problems she was having with her husband. She started to get into it, but I really don''t want to know this stuff!"

Deciding that knowledge is power, I went ahead with the testing. After relieving me of $650, Veldman began to scrape my walls and windowsills of mold. Some incomprehensible machine sucked invisible spores out of thin air. What I had thought was a layer of unscrubbable grime that had settled onto the paint in my house was actually mold.

My past attempts at cleanup had only made the mold problem worse. Unfortunately, as Veldman explains, when we scrub mold ourselves, we simply release spores all over our environment, which spreads the unwanted guest.

Mold, according to Veldman, either makes you sick by the toxic chemicals it releases into the air or weakens your immune system, especially if you have allergies. Stachybotrys was discovered decades ago in England when farmers started dying off because the hay they baled was full of the mold.

The good thing about stachy--as it''s called by those who know it well--is that it won''t grow unless the dwelling suffers prolonged water problems. It takes other less toxic molds, such as penicillium and aspergillus, only about five hours in a wet environment to roar into full-tilt horror.

The bathroom is a mold''s best friend.

A Midnight Call to Portugal

A week later, I was faxed my home''s mold report. The lab results were cryptic. Aspergillus? Penicillium? What did these microscopic spores permeating my house mean in real-life terms?

I made a frantic phone call to Portugal and woke my dad, a doctor, at 4am his time. Should I take the kids and evacuate? Tonight? Do we have a few more weeks?

My dad had never heard of toxic mold. Turns out most people haven''t.

Veldman referred me to a doctor who specializes in mold-related illnesses, who did not return my frantic phone calls. A 2am trip to the emergency room with my 7-month-old son got him a diagnosis as having croup, a virus that causes breathing difficulties.

I asked the ER physician if it could be related to the mold in our house. He shrugged his shoulders. Probably not. Who knows.

A trip to our pediatrician resulted in religious quotations and quirky direction: "The Bible says if you can''t get rid of the mold, burn the structure." Thanks for lessening my confusion, Doc.

I decided I had no choice but to proceed with the cleanup process. A quick phone call to Ream Construction, a Sand City disaster cleanup company, got me scheduled for the following week.

I stopped worrying.

Then I got the bid.

Whoa!--$5,000! That''s right, five grand to seal off my house like a toxic waste site and vacuum out all the yucky mold spores.

Veldman returned to our home for more extensive testing. This time, he located Stachybotrys spores, one of the most lethal types of mold. Evacuation was the order of the day.

We checked into a motel while Ream Construction sealed off our entire house and started sucking out mold.

The process is complicated. As Veldman explains, mold is eradicated like asbestos. An airtight containment system removes the pesky thing from the surfaces of the house, a fungicide is sprayed all over the place and visible mold is sanded off. "In the Texas case," Veldman informs, "they let it go too long--they had mold actually growing in their lungs."

Other local folks have horror stories of their own. Veldman tells the scary tale of a Santa Cruz couple and their baby who were having horrible headaches and bloody noses. "Their landlord wouldn''t believe them that they had mold, and the testing was delayed so long that the husband lost his driver''s license because of seizures he was having and couldn''t go to work anymore. When the testing was finally completed, the lab gave up counting because the samples were infested with just about every species of mold.

"They took the landlord to court after they found microtoxins in their blood." Veldman continues. "All their possessions ended up destroyed, and they moved to a new house, which they had checked for mold. They forgot the attic, and it turned out it had mold in the beams." You never know.

Mold isn''t limited to homes. So far Veldman has tested Greenfield Unified and North Salinas High School. Part of the prevalence of mold today is that newer structures use wood that''s not kiln-dried or pressurized.

Veldman has seen homes being framed in northeast Salinas "with 2-by-4s already black and caked with mold," he says. "It''s cheap wood--a porous pine species that''s already wet and never heat dried. The mold grows instantly."

In fact, one of the benefits to having an older home like mine is that the wood is kiln-dried and much more resistant to mold growth. But after being educated to its toxic effects, I still find myself apprehensive.

My family''s health has improved since the house was cleaned. I wake up without my normal scratchy throat. The kids'' noses aren''t running constantly. But, per Veldman''s advice, I keep my bathroom window open all the time, and the heat turned up high.

Now I lay in bed at night, the silence broken by the whirring of air purifiers, wondering, Did I wipe down the bathroom floors enough? Should the heat be set higher and more windows left open? Will the mold come back?

It really is the stuff of nightmares.