In this third installment of our interview with new CTEH Senior Medical Toxicologist Dr. Michael G. Holland, we explore more of his research and expertise, focusing on diethylene glycol and the controversial topic of arsenic in food products.

Tell us about your article, “Diethylene Glycol: Widely Used Solvent Presents Serious Poisoning Potential” – Can you provide some basics about that? What should people know about diethylene glycol? What are some of its common uses? What makes it so dangerous? 

At high enough doses, diethylene glycol can cause permanent renal failure/kidney failure and neurologic injury. The first poisoning was 1937 in the U.S. – a pharmacist mixed it in a liquid antibiotic preparation and 106 people died. Originally, medical professionals thought it was metabolized by splitting its ether molecular bond into two molecules of ethylene glycol- antifreeze; however, it’s metabolism is different and produces much more toxicity that ethylene glycol, and the effects are far worse than could have been imagined. It is a severe neurotoxin that scientists were unaware of because most of the victims died early before the cause could be detected. If someone suffering from diethylene glycol poisoning does survive the renal failure phase by having dialysis, they can develop severe neurological disorders and their central and peripheral nervous system can be severely affected. A significant part of this tragedy historically has been that people used diethylene glycol to cut corners  in formulations that called for the more expensive glycerin. This substitution caused hundreds of poisonings unbeknownst to the treating phsyicians because diethylene glycol was not listed as an ingredient.

In everyday life, be cautious of wallpaper stripper, brake fluid, certain brake line treatments, and stage fogging products, as they all contain or have contained diethylene glycol and should be kept in controlled environments. Diethylene glycol is an ether bond between two ethylene glycol molecules.

Staying on this same theme – you’ve written about arsenic and apple juice – what were the conclusions there and what should people understand about that?

Your basic take-home is that arsenic is the 11th most abundant element in the earth’s crust. Trace amounts are everywhere. Certain areas of the world have a high content in rock formations, so that area may have higher levels in its drinking water supply. In January of 2001, the EPA and WHO decided that 50 parts per billion in water (which was previously the max safe level) was too high and lowered it to 10 parts per billion. They gave all municipal water supply providers a five-year lead to get  arsenic levels down to 10ppb.  They did this to establish a higher safety margin.

In 2010, apple juice and some grape juices were found to have higher than the new level of 10 parts per billion, but still below 50ppb, the old safe standard. Motts, Apple & Eve Organics, and Walmart’s juices were found to contain between 25 and 35 ppb of arsenic. Juicy Juice, Minute Maid, Tree Top, and Target’s Market Pantry did not surpass the FDA’s “level of concern” for juice, but each surpassed the EPA’s allowable limit for arsenic in drinking water, with 12 to 24 ppb. Even though the juice did not meet the standards set by the EPA, the FDA considered them to be safe. Consumers will not drink enough of the juice in one day to cause a problem. Regardless, the findings created public hysteria about arsenic in apple juice.

The public also has been concerned about arsenic in other foods, like foods that contain brown rice. Rice may contain a higher level of arsenic than other grains.  However, the level of arsenic in brown rice is such a small component that it’s likely no significant risk. Also, it’s not the only thing you’re eating; so high levels of exposure are unlikely.