Jana is the coordinator of the departments two Master's programmes in Environmental Science; Environmental Toxicology and Chemistry (ETC), and Atmosphere, Biogeochemistry and Climate (ABC). She teaches environmental chemistry on bachelor and master levels in several courses (KZ4007, MI7009, MI7014, MI7019, KA3000, MI2007, MI8021); addressing history of environmental awareness, chemical management through time, basic chemical distribution and fate, sampling, quantitative and qualitative chemical analysis, exposure and risk assessment, basic endocrine disruption, early warning systems, suspect screening, non-target analysis, and effect-directed analysis. 

Her aim is to raise awareness about the complexity of chemical management and risk assessment, and to illustrate the importance of understanding and acting accordingly. She has also been invited to introduce and discuss the field of environmental organic chemistry at courses outside the topic at other universities, for example Gothenburg University (ecotoxicology), Uppsala University (toxicology for medical students), summer research school in Karlskoga (collaboration between Örebro University, Stockholm University and KTH), UNIS (the University Centre in Svalbard).

Jana’s expertise is within the framework of One Health, specifically studying pet animal and human chemical exposure and health. She has been the PI for two directed FORMAS calls addressing exposure and assessment of chemical mixtures; MiSSE (exposure to mixtures in cats) and RiskMix (risk assessment of mixtures). She is currently the PI for FELIX (cats’ exposure to PFAS and links to endocrine disease, Formas yearly) and ReproManDo (setting up a human and dog cell-based assay to study spermatogenesis, VR-3R).

As an environmental chemist Weiss has over two decades been involved in developing and applying qualitative target analysis methods to assess the exposure of a wide-range of regulated and currently used chemical contaminants. Already in her early research she applied identification strategies of new and emerging risk chemicals (NERCs), using suspect and non-target screening, effect-directed analysis and market data from the Swedish Product register, hosted by KEMI.

In 2009, she was first to report that PFAS have a binding potency to the thyroid hormone transport protein transthyretin (Weiss et al. 2009), and in 2020 a mixture risk assessment was conducted on the most complex chemical mixture thus far (n=25), showing a risk for thyroid hormone disruption in a sensitive population (children) (Hamers et al 2020). In RiskMix, a database of >400 organic synthetic chemicals analyzed in human blood worldwide and risk assessed them (Engelhardt et al. 2022 and 2025). Based on that, several mixtures were created, which in combination constitute 50 chemicals with a molar ration of human relevance. Currently, those chemical mixtures are being analyzed for their toxic potency using a wide range of approaches. In ReproManDO we use Sertoli and Leydig cells to study effects on the spermatogenesis; in RiskMix the zebrafish embryo has been exposed and the metabolomics and streoidomics will be analyzed. In collaboration with other research groups, we have provided them with this mixture to gain as much information as possible regarding the potential effects coming from this exposure.

The chemical exposure to man and pets is continuously being explored and new risk chemicals added to the complex exposure mixture. 

Team at SU:

Post Doc. (former PhD student) Josefin Engelhardt. Thesis title “Exposure to Chemical Mixtures and Associated Health Risks – Focusing on Endocrine Disruption and the Swedish General Population”. Defended March 2025. Pressrelease at SU

PhD student Dandan Zhao. Project title “Investigating Endocrine-Disrupting Chemical Exposures in Pet Cats: A Holistic Exposome Approach Linked to Health”. Co-supervised by Bénilde Bonnefille.

Former master’s student Molly Jansson. Thesis title “Per- and polyfluoroalkyl substances (PFAS) exposure to domestic cats – with focus on cat hair and indoor dust”. Defended 2024

Former master’s student Linus Arvstrand. Thesis title “Target analysis of synthetic phenolic antioxidants in human serum, prioritized by using an exposure index applied to the Swedish Products Register”. Defended 2021

Former bachelor student Norra Boone. Thesis title “Method development and evaluation for the analysis of synthetic phenolic antioxidants in blood”. Defended 2023

And many more students…

Co-supervision of PhD students outside SU:

Linus Wiklund, IMM, Karolinska Institute, Stockholm, Sweden. Thesis title “Advancing assessments of endocrine disruptors using Adverse Outcome Pathways and novel methodologies”. Defended 2025

Ike van der Veen, VU University, Amsterdam, The Netherlands. Thesis title “Analysis of per- and polyfluoroalkyl substances (PFASs) in outdoor wear”. Defended 2022.

Frank Menger, SLU Uppsala, Sweden. Thesis title “Hidden in the Water - Development of screening strategies to identify new organic contaminants of emerging concern”. Defended 2021.

Johannes Pohl, SLU, Uppsala, Sweden. Thesis title “Ozonation as sewage effluent treatment Toxicological effects in adult and embryonic zebrafish”. Defended his licentiate 2018 and PhD 2020.

Martin Brits, shared degree between VU University, Amsterdam, The Netherlands and NMISA, Pretoria, South Africa. Thesis title “Flame Retardants in the South African Indoor Environment”. Defended 2020.

Cornelius Rimayi, shared degree between VU University, Amsterdam, The Netherlands and University of Witwatersrand, Johannesburg, South Africa. Thesis title “Distribution of Persistent and Pseudo-Persistent Organic Pollutants in Rivers Draining Urbanised Catchments in South Africa”. Defended 2018.