Along with rapid economic growth and enhanced agricultural productivity, particulate matter emissions in
the northern cities of Thailand have been increasing for the past two decades. This trend is expected to continue
in the coming decade. Emissions of particulate matter have brought about a series of public health concerns,
particularly chronic respiratory diseases. It is well known that lung cancer incidence among northern Thai
women is one of the highest in Asia (an annual age-adjusted incidence rate of 37.4 per 100,000). This fact has
aroused serious concern among the public and the government and has drawn much attention and interest
from the scientific community. To investigate the potential causes of this relatively high lung cancer incidence,
this study employed Fourier transform infrared spectroscopy (FTIR) transmission spectroscopy to identify the
chemical composition of the PM2.5 collected using Quartz Fibre Filters (QFFs) coupled with MiniVol™ portable
air samplers (Airmetrics). PM2.5 samples collected in nine administrative provinces in northern Thailand before
and after the “Haze Episode” in 2013 were categorised based on three-dimensional plots of a principal component
analysis (PCA) with Varimax rotation. In addition, the incremental lifetime exposure to PM2.5 of both genders
was calculated, and the first derivative of the FTIR spectrum of individual samples is here discussed.