John Parsons completed his PhD in environmental chemistry at the University of Amsterdam in 1988. After working a while outside of academia he returned to the UvA in 1991 and stayed here as researcher and lecturer for the rest of his career. Together with Prof. dr. Harrie Govers, Dr. Kees Olie and Dr. Pim de Voogt, John constituted the academic staff of the Department of  Environmental and Toxicological Chemistry (MTC) in the period 1991-2000. The focus of MTC´s research was on the fate and effects of persistent organic pollutants (POPs), in particular chlorinated dioxins and furans, polychlorinated biphenyls and brominated flame retardants. John´s interest was directed to the sorption, biodegradation and bioavailability of POPs and his expertise in these fields was soon recognized internationally. He became a welcome speaker at international conferences such as those of the Society of Environmental Toxicology and Chemistry (SETAC).

As member of the MTC group, John joined IBED when the institute was founded in 2000. Upon subsequent restructuring of IBED through the years his homebase shifted first to the Earth Surface Science group and later the Ecosystem and Landscape Department (ELD). This allowed him to broaden his scope and develop a unique environmental chemistry profile integrating both aquatic and terrestrial ecosystems; and serve as a bridge-builder between the aquatic and terrestrial departments within IBED, whilst also maintaining strong ties with chemistry institute HIMS.

John led and participated in several large EU projects, including ABACUS, a project studying the bioavailability of organic contaminants, and FIRE, aimed at studying the fate and effects of brominated flame retardants and their non/halogenated alternatives. The project on alternative flame retardants marked the bridge between environmental chemistry and ecotoxicology, testing both the environmental fate and effects of these compounds. A review identifying POP contamination sources in omnivorous seabirds even connected three of the four IBED departments. An MSc literature review supervised a.o. by John was published as a review article in 2012 at the onset of the plastic hype and has been cited no less than 285 times.

John was not only a great researcher, but also a great teacher. Here, again he served as a bridge-builder and contributed to the bachelor and master programs of Future Planet Studies, Earth Science, Biology and Chemistry in courses ranging from Environmental Chemistry to the interdisciplinary course Energietransities. He was also the prime supervisor of many successful PhD studies and his students loved John´s erudite knowledge of the microbial biodegradation of chemical pollutants.

After his formal retirement in 2018, John remained active as a scientist. He kept his desk at the University and was regularly seen there discussing research results with students and colleagues. He joined the Dutch ARES group (Association of Retired Environmental Scientists) in 2019 where he became very active  in projects dedicated to defining persistency. Right before his retirement, in collaboration with colleagues from IBED and HIMS as well as many foreign partners, he had secured funding for yet another EU Project: LEX4BIO. This project, which focusses on creating circular nutrient loops via the use of biobased fertilizer, whilst avoiding soil and crop pollution with anthropogenic substances, is still running today. John intensively contributed to the supervision of the postdoc and PhD students within the project until the very end; he sent a last e-mail message with feedback on a manuscript arising from the project four days before he passed away. This is testimony to John’s devotion to science and teaching, particularly to the PhD students and junior researchers he mentored. John was a great scientist, a modest and exceptionally kind man, and a great team player, making it a pleasure and privilege to work with him. He will be dearly missed by us. Our thoughts are with his family.