Disputation: Helene Lunder Halvorsen

Doctoral candidate Helene Lunder Halvorsen at the Department of Chemistry, Faculty of Mathematics and Natural Sciences, is defending the thesis "Sources and processes controlling the occurrence of legacy POPs and organic contaminants of emerging concern in European air" for the degree of Philosophiae Doctor.

Image may contain: A woman (Helene) is looking straight at the camera and smiling. She is wearing a dark green shirt, standing against a white background.

Helene Lunder Halvorsen 

The Disputation will be live streamed for everyone else.
The livestream will be activated 15 minutes before the Defense starts.

Trial lecture

October 25th, 13:00 PM, Auditorium 2, Chemistry building

Trial lecture title:

Mercury pathways from sources to ecosystems and humans – past, present and future

Kreeringssammendrag/Conferral summary 

Til tross for lavere utslipp av regulerte miljøgifter, kan både de og stoffer som lages for å erstatte dem utgjøre en risiko for mennesker og miljø. I dette arbeidet har forekomsten av utvalgte miljøgifter blitt undersøkt i luftprøver fra avsidesliggende områder i Norge og Europa. Fokus har vært på å vurdere hvorvidt nivåene i lufta er påvirket av nye eller historiske utslipp, enten lokalt eller tilført langveisfra.

Main research findings

Persistent Organic Pollutants (POPs) are chemicals that have harmful impact on human health and the environment. POPs are now regulated but were previously widely used in different applications as additives in products and as pesticides. Despite emission reductions, possible unintentional emissions may persist. Also, alternative chemicals have been introduced, which may have similar properties to POPs.

In this work, European air samples from 2016 were used to investigate the occurrence, distribution and sources of POPs and the replacement chemical dechlorane plus. The emphasis was on Norway and the Arctic. The investigation was done by combining analysis data from a national and regional sampling campaign with data from source-receptor models.

The study showed higher concentrations of most POPs and dechlorane plus in densely populated regions in Europe, than in the more remote regions. The occurrence of POPs in remote regions supports their potential to travel far from their source of origin. Re-emissions from previously contaminated surface media were shown to affect the concentrations of most POPs across the region, while ongoing emissions were indicated for dechlorane plus and the byproduct PCB-11 (3,3’-dichlorobiphenyl). Hexachlorobenzene differed from the other POPs with higher concentrations at northern latitudes than southern-, and with higher concentrations compared to a similar campaign from 2006.

Image may contain: A woman (Helene) standing in a forest, holding an aluminium bowl in one hand and aluminium foil in the other. She is looking down and is wearing beige shorts and a dark blue polo shirt.

 

Candidate contact information

ResearchGate: https://www.researchgate.net/profile/Helene-Lunder-Halvorsen

Email: hlu@nilu.no

 

Published Oct. 11, 2023 11:28 AM - Last modified Oct. 11, 2023 1:30 PM