Abdul Wahab Khan
Panaji
Presence of potentially hazardous polycyclic aromatic hydrocarbons (PAHs), including the carcinogenic Benzo[a]pyrene, along with Pyrene and Acenaphthene, has been confirmed in water samples collected from several major rivers across Goa.
According to a recent study by researchers from the National Forensic Sciences University (NFSU), Goa campus, the contamination is attributed to sources such as industrial effluents, urban runoff, coal and petroleum combustion, mining-related activities, oil spills, road construction and biomass burning, all of which are known contributors of PAHs in aquatic ecosystems.
Published in the January-June 2025 edition of the NFSU Journal of Forensic Science, the investigation was undertaken to assess pollutants in Goan rivers that may threaten aquatic ecosystems and communities dependent on the river water for domestic use.
Water samples were collected from six strategic locations across Goa: Ferry point at Divar Island on Mandovi River, Khandepar River near Saptakoteshwar Temple, Mandovi River Front, Nerul River near Aguada Fort, Rachol Old Port on Zuari River and Rachol ferry point on Zuari. The samples were analysed using High-Performance Liquid Chromatography (HPLC) and Mass Spectrometry after extraction with ethyl acetate.
The laboratory analysis revealed recurring chromatographic peaks across all samples, indicating the presence of aromatic pollutants. Mass spectrometric analysis identified Acenaphthene, Pyrene, and Benzo[a]pyrene as the principal PAHs present in the river waters.
Researchers reported that Acenaphthene was found in “significant concentrations” and appeared persistent in the environment, while Pyrene was detected in “high concentrations especially in water samples collected near sediments,” suggesting contamination from industrial discharges and urban runoff.
Most concerning was the detection of Benzo[a]pyrene, which the report describes as “a known carcinogen.”
The study notes that the World Health Organisation’s (WHO) guideline value for Benzo[a]pyrene in drinking water is 0.7 micrograms per litre, 0.8 for Pyrene and 0.1 mg/m³ for Acenaphthene, highlighting the latter as the benchmark carcinogenic compound among the detected PAHs. While the researchers confirmed its presence, the report did not quantify the exact concentration of Benzo[a]pyrene, Pyrene or Acenaphthene detected at each sampling location. Instead, the compounds were identified through characteristic mass-to-charge ratios and chromatographic retention times.
Discussing the health impacts, the researchers warned that PAHs are highly stable, degrade slowly and tend to accumulate in sediments and aquatic organisms. The report states that “PAHs can have long-term consequences on aquatic ecosystems, including mutagenic and endocrine-disrupting effects, even at low levels.”
It further cautions that human exposure may occur through the ingestion of contaminated water, consumption of aquatic organisms and skin contact, specifically identifying Benzo[a]pyrene as a pollutant associated with carcinogenicity and mutagenicity.
The study, titled ‘Assessment of Polycyclic Aromatic Hydrocarbon Contamination in Goan River Water: Toxicity and Persistence Concerns,’ was conducted by Muskan Bindal, Chinmay Anand, Ranadip Bhowmik and Assistant Professor Sneha R Sagar of NFSU Goa.
