Abstract:
Cement manufacturing is a process that results in the emission of significant quantities of
suspended particulate matter (SPM) to the ambient air. An environmental forensic investigation was carried out in the surroundings of a major cement manufacturing unit at a place
called Coimbatore in the southern Indian state of Tamil Nadu. The investigation was carried
out to identify the contribution of the cement manufacturing unit to the SPM concentration
of the surrounding air environment. The sampling points’ selection and sample collection
were done following the principles outlined in the INTERPOL Manual for Pollution Crime
Forensic Investigation. On-site monitoring of the air samples was carried out using Mini
Laser Aerosol Spectrometer (GRIMM, Mini-LAS Model 11R). The instrument was capable of
measuring particles ranging from 0.25 to 32 mm and classifying them into 31 size channels.
The test results at majority of the monitoring locations were well above the limits specified
in the National Ambient Air Quality Standards of India. Microscopic studies of the dust samples were carried out for surface texture and particle shape. The spatial distribution of particles was analysed using geographic information system (GIS) for the visual identification of
the extent of the pollution by keeping the cement factory as the focal point. The results
from the GIS and microscopic analysis established the role of the cement factory in the particulate matter pollution of its surroundings, specifically in the areas North-West of the
factory. The successfully adopted procedure can serve as a guideline for the environmental
forensic investigation of similar pollution incidences.
