Inhaling Disinfectant Chemicals May Cause Significantly Greater Lung Injury Than Ingestion, Study Suggests

A recent study led by researchers at the University of California, Davis, suggests a critical finding: inhaling common disinfectant chemicals, known as quaternary ammonium compounds (QACs), may cause significantly greater lung injury than ingesting them. This research, conducted on mice, identified substantial lung damage at QAC exposure levels in the blood that were comparable to levels measured in humans.

These findings raise questions regarding the potential role of airborne exposure from disinfectant products in contributing to respiratory conditions.

Understanding Quaternary Ammonium Compounds (QACs)

Quaternary ammonium compounds (QACs) have been a staple in cleaning products and disinfectants since the 1940s. These versatile chemicals are found in a surprising array of everyday items.

QACs are present in numerous items, including disinfectant sprays from brands like Lysol and Clorox, Roccal, herbicides, eye drop disinfectants, nasal sprays, mouthwash, dryer sheets, and fabric softeners. While the toxicity of QACs upon accidental ingestion has been long established, the recent UC Davis study specifically explored the effects of inhalation.

Key Study Findings: Inhalation vs. Ingestion

Scientists at the University of California, Davis, exposed mice to airborne QAC particle levels similar to what humans might encounter when using disinfectants in a typical home environment. The results were stark: the study demonstrated that when QACs entered the airway, they led to significantly greater lung injury compared to oral ingestion.

Dr. Gino Cortopassi, a biochemist and pharmacologist at the UC Davis Weill School of Veterinary Medicine and lead author of the study, reported a dramatic difference:

"Inhaled QACs caused 100-fold more lung injury and lethality in mice than oral ingestion."

The research also indicated a crucial link to human health: blood QAC levels in mice experiencing lung harm from inhalation were comparable to those found in human blood. This suggests that inhalation via spray cleaners and similar products may be a primary route for these chemicals to enter the human body.

Broader Health Implications and Prior Research

This new research builds on previous work by the same team. In 2021, their study detected QACs in the bloodstream of 80% of human participants. This earlier research found a concerning correlation between higher QAC blood levels and lower mitochondrial energy levels.

Mitochondria are the cellular components vital for energy generation. Reduced mitochondrial energy production has been linked to conditions such as chronic fatigue, muscle weakness, and cognitive impairment.

Beyond these mitochondrial effects, QAC exposure has also been associated with a range of other health concerns, including skin and eye irritation, inflammation, metabolic disruption, asthma, and chronic obstructive pulmonary disease (COPD).

The recent study was published in the journal Environmental Science and Technology and received funding from the National Institutes of Health's National Institute of Environmental Health Sciences.