Hair can record chemical exposure ^{CEFR B2}

New research from the University of Texas at Austin shows that human hair can serve as a detailed record of chemical exposure over days, weeks and months. Because hair grows slowly, different sections correspond to different times, allowing researchers to reconstruct exposure timelines that blood or urine tests miss.

Anna Neville began by testing a lock of her own hair in Pawel Misztal's indoor air chemistry class. Heating intact strands released embedded molecules that a proton transfer reaction time-of-flight mass spectrometer — the lab "sniffer" — identified in real time. Unlike conventional hair analysis that requires grinding and chemical extraction, this approach scans intact strands and speeds detection with less sample preparation.

Analyzing donated hair bundles, the team detected more than 1,000 compounds, including phthalates and residues from cigarette smoke. The study, now published in Chemical Research in Toxicology, notes that much exposure happens indoors; Americans spend about 90% of their time inside and indoor sources often dominate the pollutants people inhale. Pilot funding came from Whole Communities–Whole Health, a UT grand challenge research program.

• Practical steps to reduce exposure include vacuuming more often.
• Avoid personal care products that contain phthalates.
• Open windows briefly to flush indoor air.

Researchers stress practical engineering solutions to improve indoor air quality rather than alarm. The method offers a new way to study how everyday environments relate to long-term chemical exposure.