# Exposure to Quaternary Ammonium Compounds (QACs) in Assisted Living Facilities: Implications for Older Adults

## TL;DR

This study measures quaternary ammonium compounds (QACs) in assisted living facilities, finding high levels in dust and wristbands, with potential health risks for residents and staff.

## Contribution

First comprehensive assessment of QAC exposure in assisted living facilities using dust, air, and wristband samples.

## Key findings

- QAC concentrations in dust were significantly higher in assisted living facilities compared to US residential households.
- Benzylalkyldimethylammonium compounds (BACs) were the most abundant QAC group across all matrices.
- Dust ingestion is the main exposure route for QACs in these facilities.

## Abstract

Quaternary ammonium compounds (QACs) are commonly used
in disinfecting
and personal care products for their antimicrobial, surfactant, and
preservative properties. This study provides the first comprehensive
assessment of QACs in assisted living facilities through the analysis
of 19 QACs from three different QAC subgroups in indoor dust and air
samples collected from three assisted living facilities in Indiana,
United States (US), as well as in wristbands worn by the residents
and staff of these facilities. The medians of the total QAC concentrations
(∑QAC, the sum of 19 QAC concentrations) were 151,000 ng/g
in dust, 3.17 ng/m3 in air, and 2,290 ng/g in wristbands.
Benzylalkyldimethylammonium compounds (BACs) were the most abundant
QAC group in all three matrices and contributed 58–87% to the
∑QAC concentrations. The QAC distribution patterns found in
dust, air, and wristbands were similar to those reported for disinfecting
products, suggesting these products could be an important indoor source
in assisted living. QAC concentrations in wristbands worn by staff
during their work shift were significantly higher than those in wristbands
worn by residents (p < 0.05). In addition, the
levels found in dust from assisted living were several times higher
than those previously reported in US residential households. Concentrations
of C12-, C14-, and C16-BACs in dust, air, and wristbands significantly
and positively correlated, suggesting common sources in the indoor
environment. Estimated daily intake (EDI) of QACs suggests that accidental
dust ingestion is the predominant exposure route, accounting for approximately
62% of the total QAC intake. The elevated QAC concentrations in assisted
living facilities are of concern for the residents and staff of these
facilities because of the potential health risks associated with exposure
to these chemicals, such as respiratory effects.