Plants as a Bio indicator for Assessing Micro plastic Contamination in Bottled Drinking Water

Abstract

Aquatic plant, specifically Lemna minor (duckweed), Nasturtium officinale (watercress), and Eichhornia crassipes (water hyacinth), were selected as bio indicators owing to their heightened sensitivity to pollutants and their capacity to exhibit distinct morphological and physiological alterations upon exposure to contaminants. The consumption of bottled water has witnessed a significant rise in Iraq and globally, attributed to its perceived purity; however, the plastic packaging utilized may disintegrate into micro plastics that subsequently contaminate potable water and pose threats to human health as well as ecological systems. The objective of this investigation was to assess micro plastic contamination in bottled drinking water by employing an integrated approach of spectroscopic analysis (FTIR) alongside responses from plant bio indicators. A total of ten local bottled water brands were subjected to sampling, filtration, and evaluation through fluorescence microscopy to ascertain particle morphologies, coupled with FTIR spectroscopy to identify polymer types, while aquatic plants were subjected to contaminated samples under meticulously controlled laboratory conditions and observed for growth rate, leaf pigmentation, root deposition, chlorophyll concentration, and enzymatic activity. The findings indicated that pellet-shaped particles were predominant across the majority of brands (e.g., Sama 96.1%, Al-Kawthar 91.6%), whereas fibrous particles were most prevalent in Louloua (50%) and Al-Rawiyah (71.1%). FTIR analysis corroborated the detection of polymers including ABS, PP, PET, PVC, PMMA, and Cellophane; nevertheless, certain brands exhibited no identifiable micro plastics. The plant assays revealed biological responses indicative of stress: Lemna minor demonstrated a decrease in frond size and chlorophyll content, Nasturtium officinale displayed leaf chlorosis and inhibited growth in fiber-dominant samples, and Eichhornia crassipes evidenced root deposition of particles, particularly PET and ABS, alongside heightened antioxidant enzyme activity suggesting oxidative stress. Collectively, the amalgamation of plant bioindicators with spectroscopic analysis yielded compelling evidence of microplastic contamination in bottled water, emphasizing potential risks to both human health and ecological integrity while endorsing the utilization of aquatic plants as efficacious biological markers for the assessment of bottled water quality.