Particle toxicology – Hanna Karlsson's group

We conduct research with focus on understanding toxic effects, underlying mechanisms and health risks of various particles including urban air pollution nanoparticles, particles from occupational settings (welding, 3D-printing) as well as nano- and microplastics.

Research outline

The Karlsson group mainly works with exploring toxic effects, underlying mechanisms, and human health risks of various particles in the air. Current projects focus on nanoparticles from different transport modes (Vallabani et al., 2024), particles from welding and 3D-prtinting (Karlsson et al., 2024) as well as nano- and microplastics. Other aspects include modelling of particle retention in the lung (McCarrick et al., 2022), air-liquid interface exposures, and investigating skin sensitizing properties of chemicals (Karri et al., 2021).


Toxic effects of nanoparticles from different types of transport

In the EU project "nPETs", we study nanoparticles that are formed by different modes of transport (road traffic, subway, shipping, etc.). The project includes comparing toxic effects of nanoparticles from different sources using different cell methods such as exposure of cells in the "air-liquid interface" and to develop “toxicity scores”. We also model the retention of nanoparticles in the lung.

Read this review: Toxicity and health effects of ultrafine particles: Towards an understanding of the relative impacts of different transport modes

Toxic effects of welding particles and particles from 3D printing

In projects performed in collaboration with KTH and several industrial partners, we study the toxic effects of welding particles and of powders used in so-called "3D printing". New welding wires have been developed by industry partners, and we have shown that particles formed during welding with these release significantly less hexavalent chromium and they are less toxic compared to those generated from welding with the traditional wires (see e.g McCarrick et al., 2021). In studies on powders used in 3D printing, or particles formed in the process, we have so far seen limited toxicity (see e.g. Vallabani et al., 2022).

Read more here: Health hazards of particles in additive manufacturing: a cross-disciplinary study on reactivity, toxicity and occupational exposure to two nickel-based alloys

Read about modellig here: Modelled lung deposition and retention of welding fume particles in occupational scenarios: a comparison to doses used in vitro

Effects of nano- and microplastics

In society today, there is a lot of focus on so-called nano- and microplastics – small plastic fragments that are found in air, water and in the food we eat. In an ongoing project, we are studying whether nano- and microplastics can cause harmful effects on cultured cells. The first results show low toxicity in short-term studies.

Read more about the project here: Towards quantifying impacts of microplastics on environmental and human health

Skin sensitizing properties of chemicals and mixtures

Anyone who has skin contact with allergenic substances can develop contact allergy (sensitisation) and those who have become allergic develop eczema after subsequent contact with the substance. Chemicals from medical devices and textiles are studied in on-going projects. We are working with KeratinoSens assays as well as with a co-culture of skin cells and immune (Karri et al., 2021).


All publications from group members