Table 2.

Biological specimens for detection of microplastics. Microplastic contamination was found in biological specimens such as blood, sputum, meconium, faeces, saliva, bronchoalveolar lavage fluid, and placenta

Study participants	Locations	Technique of analysis	Polymer types	Reference
Three meconium, six infants, and ten adult faeces	New York	Mass spectrometry	Polyethylene terephthalate and polycarbonate	Zhang et al. (2019)
Faeces of patients with inflammatory bowel disease and healthy people	China	Raman spectroscopy	Polyethylene terephthalate and polyamide	Yan et al. (2022a)
Faeces of eight healthy volunteers aged 33 to 65 years	Europe and Asia	Fourier transform infrared spectroscopy	Polypropylene and polyethylene terephthalate	Schwabl et al. (2019)
Sputum of 22 patients suffering from different respiratory diseases	China	Fourier transform infrared spectroscopy	Polyurethane polyester, chlorinated polyethylene, and alkyd varnish	Huang et al. (2022a)
8000 samples of saliva from adult	Iran	Raman spectroscopy	Not detected	Abbasi and Turner (2021)
Bronchoalveolar lavage fluid from 44 adult patients undergoing a bronchoscopy	Europe	Fourier transform infrared spectroscopy	Microfibres (rayon/viscose polyester cellulose and cotton)	Baeza-Martinez et al. (2022)
Blood samples from 22 healthy volunteers	Netherlands	Fourier transform infrared spectroscopy	Polyethylene terephthalate, polyethylene, and polymers of styrene	Leslie et al. (2022)
Placenta from healthy women and have a vaginal delivery	Italy	Raman microspectroscopy	Polypropylene	Ragusa et al. (2021a)
Placental tissue and meconium specimens during two caesarean sections for breech deliveries	Austria	Fourier transform infrared spectroscopy	Polyethylene, polypropylene, polystyrene, and polyurethane	Braun et al. (2021b)

The widespread contamination of microplastics is a concerning issue.