Tuesday, 08 October 2019 18:07

Home buyers, beware: Contamination from cooking meth can linger for years

brought the messy, smelly process of cooking methamphetamine into American households with its depiction of a high school chemistry teacher who begins making the stuff after a terminal cancer diagnosis. Walter White went from cooking meth in an RV, to a home basement, to a full-fledged underground lab run by a crime syndicate.

It's highly likely that any place he cooked would still be contaminated years later, according to a new study published in the International Journal of Environmental Research.

Researchers at Flinders University in Australia took samples from a house in rural Victoria, Australia, once used to cook meth and found the house still contained significant levels of the drug even five years after the drug operations had ended. And that contamination had transferred over to personal possessions of the home's new owners.

"Our results demonstrate that methamphetamine has continued to mobilize after manufacture when the property was under new ownership for a period exceeding five years," said co-author Kirstin Ross. "This suggests that the methamphetamine is not breaking down or being removed and is constantly transferred from contaminated to non-contaminated objects."

Australian police seized chemicals and cooking equipment from the house in question in May 2013. The police notified the local council that the home had been used to cook meth and thus posed a potential health risk. It was supposed to undergo remediation to clear any lingering contamination, but for some reason this didn't happen. A family of five (two adults, and children aged 7, 8, and 11 years) bought the home in August of that year, unaware of its prior history. They didn't find out until March 2014, and when environmental testing revealed levels of methamphetamine well above the Australian limit, the family was forced to vacate the home.

A 2015 study found significant traces of meth in hair samples taken from the family members. Although no family member had ever used meth or were taking any amphetamine-based medications, there were traces at concentrations ranging from 5 to 460 pg/mg. The two youngest children had the highest levels, probably because they had the lowest body weight and were exposed more as they played around the house.

All family members reported some adverse health effects—sore and watery eyes, dizziness, blurred vision, persistent coughs—but the youngest boy was the most affected. He developed asthma-like symptoms, had trouble sleeping, and began demonstrating behavioral changes, such as anxiety, nightmares, and signs of ADHD. (A behavioral assessment of the boy conducted before the family moved into the house found no such issues, so it was most likely due to his exposure to meth in the house.)

Fortunately, most of the health and behavioral issues cleared up within a year after moving out. But the case study amply demonstrates the importance of properly cleaning such homes, since trace contamination can have a deleterious effect on young children in particular.

This new study builds on those earlier findings, to determine just how much contamination there was in the home, how much those traces were transferred to family possessions, and how long those traces lasted. The family haven't done any renovations, and the home had remained vacant in the year since they moved out. The researchers took surface wipe samples of the interior walls at various points in time, the better to monitor any changes in contamination levels. They also sampled several house materials: roof insulation, wall plasterboard, the timber frame in the hallway, carpet, blinds, and filters from the kitchen range and air conditioner. And they sampled various family-owned items: rugs, mattresses, toys, toothbrushes, cooking utensils, and vacuum cleaner bags, for instance. All the samples were then analyzed for contamination levels.

The highest levels were found in the plastic window blinds, in keeping with previous research finding high levels of meth in PVC, polyurethane, and stained or varnished wood. Those levels remained relatively consistent over several years, with no signs of degradation or decrease in surface residues. Of even greater concern, from a public health perspective, was just how much methamphetamine had been transferred to the family's belongings. "It is clear that the transference was high and that contamination is extensive," the authors wrote.

The authors questioned whether current practices regarding remediation of such sites are sufficient to determine contamination levels, given how much contamination they found in the material samples, and how much was transferred to other objects. "Without fully understanding the extent of contamination that is present, not only on surfaces but also within the building materials and surfaces/items that people are exposed to on a daily basis, it is difficult to ensure that the correct and most effective remedial approaches are taken," they wrote.

DOI: International Journal of Environmental and Public Health, 2019. 10.3390/ijerph16193568  (About DOIs).