The high-tech hunt for a harmful element

Much of Chang and Theisen's work shares characteristics with that of a detective. Once an inspector is notified of an exposure by the state, they reach out to the family, ask questions and if the exposure level is high enough, go into the home to search for clues. Certified inspectors, like Chang, conduct thorough examinations of properties, identifying potential sources of lead contamination such as lead-based paint, dust, and soil.

“When children get their bloodwork done by their physician, and it comes back positive for lead, those results will be sent to the state. And then the state will send us those results,” Chang explained. “When there are lead levels of 3.5 or more, we'll give the family a call, go over a questionnaire to try to identify where they're getting exposed to lead. At levels of 10 or above, we will do home investigations when permission is granted. During a home investigation, we take water samples, soil samples, dust, wipe samples, and we use our X-ray machine to test surfaces for lead.”

The aforementioned ray gun, actually an X-ray analyzer, is a recently acquired piece of technology obtained by Environmental Health, which uses an electric current under high voltage to produce X-rays to measure lead contamination. 

According to Chang, it has significantly improved efficiency in lead testing procedures.

"For an investigation, we usually focus on areas that the children will have access to, like window seals, the lower walls, and doors,” she said. “We can test up to 100 surfaces, so this helps us narrow down where we collect our samples. With the old device, it would take us a very long time. But with the new one, it's much quicker, taking only two seconds for a result."

The old device not only used outdated technology but also had become a costly burden in terms of both maintenance and operation.

“Near the end of its life, readings on the old device could take up to a minute,” said Dan Joseph, Director of the Weld County Environmental Health division. “When you are doing 50 or 60 samples in a visit, that adds up. Also, it was radioactive, so there were additional challenges such as sourcing, leakage testing, and radiation monitoring of staff that had to be done. Moving over to the new device eliminated all of that.”

Homes built before 1978 are generally at a higher risk of lead contamination due to the common use of lead-based paint in residential buildings before regulations restricting its use were put in place. Older plumbing systems, including lead pipes or fixtures containing lead, can contaminate the drinking water; however, the risk of lead exposure is not limited to age. Homes located near industrial areas or major roadways may have lead-contaminated soil. Lead particles from industrial activities or historic pesticide use can settle in the soil and be tracked into homes, especially in areas with high foot traffic. 

In the case Chang and Theisen investigated early this year, they used their ray gun to take more than 50 readings all over the house, all of which were negative for hazardous levels of lead contamination. On a hunch, she aimed the analyzer at the tile floor by the front door and had her answer in seconds. It turned out, the tile was covered in contaminated soil tracked in on the soles of the children’s shoes. The culprit she was looking for was not in the house after all but in the area outside where the children were playing.

While there is no enforcement action the county can take if lead is found in a home, the lead program can provide resources focused on further explaining the dangers of lead exposure and how to mitigate it. Through partnerships between local health organizations, those affected by it have the information needed to address any identified risks.

Chang, Theisen and Joseph are excited to have the latest technology to keep families safe.

“Without an analyzer, we would be very limited. We would have to be scraping off the paint on every surface that we wanted to see if there's lead. It's just not efficient,” Chang said, explaining the importance of disturbing as little as possible and that scraped-off samples need to be further analyzed in a lab, adding time and money — approximately $15 per sample — to the process.

However, the new lead-analyzing tool is making those instances a thing of the past.

 “This is the best thing we could take out there right now,” she said.

If you want to be directly transported back to the early days of Weld County, view the St. Vrain County Record Book. This book houses early records pertaining to many different topics.

The Weld County/Colorado State University Extension Office will hold the 2023 Women in Ag Conference later this week. Be sure to read the next issue of County Roots as we highlight the conference and the important role women have in helping the agricultural industry thrive,