Ioannis Sadiktsis Forskare

My current research focus is on developing methods for chemical characterization of the organic composition of particulate matter which encompasses coupled chromatographic techniques for target analysis of polycyclic aromatic compounds (PACs), and nontarget analytical workflows using high-resolution mass spectrometry.

Ongoing research projects

Chemical profiling and toxicological assessment of organic aerosols from traffic - Necessary knowledge for improved risk assessments and regulations
Formas DNr. 2021-00496, 2022-2025.

Abstract

Air pollution, which include hazardous gases and particles, causes staggering economical losses and is the largest environmental health risk factor for disease and pre-mature death. Road traffic is a large source to particles, black carbon and hazardous polycyclic aromatic compounds, and is thought to be responsible for a substantial portion of the total pre-mature deaths caused by particles. Vehicular particle emissions comprise tail-pipe emissions, different wear particles and road dust re-suspension.

Research on vehicular emissions is mostly conducted on a single vehicle or a single engine whose emissions are difficult to extrapolate to the diverse vehicle fleet actually running on the roads. To address this issue, this project will conduct sampling of collectively emitted traffic related PM10 and PM2.5 close to a heavily trafficked highway for the timespan of a whole year.

The organic fraction present on the collected particles will be characterized using nontarget analytical chemical methods using complementary instrumental techniques to obtain a comprehensive chemical profile of the organic fraction emitted from vehicular traffic. Combined chemical analyses and in vitro assays will be made to identify health relevant traffic related organic chemical compounds.

In order reduce the negative health impact from road traffic emissions it is of necessity to understand the composition of these emissions and the health risks associated with those emissions.

Project members:
Ioannis Sadiktsis (Principal Investigator), MMK, Stockholm University
Kristian Dreij, Institute of Environmental Medicine (IMM), Karolinska Institute
Oskar Karlsson, Science for Life Laboratory & Department of Environmental Science, Stockholm University
 

Azo dyes, quinolines and anilines in clothes - Daily human exposure to hazardous chemicals
Formas 2021-01540, 2022-2025.

Abstract

The global textile industry utilizes high amounts of numerous chemicals. We have observed that quinolines and anilines are compounds that often are found at high levels in clothing garments on the consumer market. The compounds are most likely by-products from disperse azo dyes, used for colouring synthetic materials such as polyester. Many of these chemicals have proven or suspected carcinogenic, mutagenic and/or skin allergenic effects, and according to preliminary results, the chemicals may stay in the garments even after several laundry cycles. We have detected levels exceeding 1 gram/kilogram in certain common clothes. Azo dyes and anilines are suspected to a play important role in textile allergy, but it is not fully known why and how. Firstly, knowledge is lacking regarding which azo dyes and anilines that are actually present in textiles on the consumer market, and at what levels. Also, it is not known how easily they can be taken up by human skin from skin-close garments. We will therefore examine skin absorption using a synthetic skin model (having similar properties as human skin), and also investigate if even more hazardous chemicals may be formed by skin enzymes. Also, we will use novel and powerful analytical tools to map the occurrence of anilines, quinolines and azo dyes in both new and recycled clothing textiles. Reuse of textiles that is safe to humans and the environment is a prerequisite for a sustainable circular economy of clothes.

Project members:
Ulrika Nilsson (Principal Investigator), MMK, Stockholm University
Ioannis Sadiktsis, MMK, Stockholm University
Conny Östman, MMK, Stockholm University
 

A new model for assessing cancer risks associated with air pollution mixtures
Formas DNr. 2019-00582, 2020–2022.

Abstract

Air pollution and airborne particulate matter (PM) are classified as carcinogenic to humans, but these complex mixtures of multiple compounds makes quantitative risk assessment a challenge. Current strategies for cancer risk assessment of air pollution are based on a pollutant-by-pollutant approach. This is clearly a simplification which excludes the possibility of interaction effects and may misestimate the actual cancer risk. Here, we address this issue by developing new methodology for whole mixture-based cancer risk assessment of air pollution. The overall aim of this project is to combine state-of-the-art methods for analysis of chemical composition of urban, diesel and biomass burning PM with traditional and high throughput in vitro testing of native PM samples in order to generate Mixture Potency Factors (MPF) estimating the carcinogenic potency of the whole mixture. Our results show that MPFs based on whole mixtures better indicate cancer potency than looking at single pollutants. The project will develop an approach that can be used for assessment of total carcinogenic effects of air PM pollution both for larger city-wide and for smaller site-specific risk assessments. Ultimately, we will improve the cancer risk assessment of airborne PM by including the obtained knowledge about whole mixture potencies in already established models for estimation of lung cancer incidence in urban environments.

Project members:
Kristian Dreij (Principal Investigator), Institute of Environmental Medicine (IMM), Karolinska Institute
Felipe De Oliveira Galvão, IMM, Karolinska Institute
Ulla Stenius, IMM, Karolinska Institute
Silvia Batistuzzo de Medeiros, Federal University of Rio Grande do Norte, Brazil,  Department of Cellular Biology and Genetics
Ioannis Sadiktsis, MMK, Stockholm University
Joakim Pagels, Ergonomics and Aerosol Technology, Lund University
Hanna Karlsson, IMM, Karolinska Institute
 

Chemical characterizations of diesel engine exhaust particles and its transformation products from renewable fuels
Formas DNr. 2018-00475, 2019–2021.

Abstract

The link between ambient particle exposure and cardiopulmonary diseases, as well as lung cancer is well established from numerous of epidemiological studies. Although not fully understood, several important factors for particle toxicity have been suggested. These include particle size, surface reactivity, and organic composition. Polycyclic aromatic compounds (PACs) has received special attention due to their carcinogenic properties and abilities to generate reactive oxygen species, thus being likely candidates among organic compounds that are driving the adverse health effects.

Vehicular traffic and in particular diesel engine exhaust is an important contributor to both fine particles and PACs in urban atmospheres. Thus, with the near future transition from fossil fuels to bio-based alternatives, implications to adverse health effects from these potentially new emissions needs to be further investigated.

This research proposal describes analytical workflows involving powerful instrumental techniques that enable us to thoroughly characterize the chemical composition of heavy-duty-diesel emission particles. Planned investigations on the how the emissions change with different biofuels, atmospheric aging and the use of emissions control techniques is expected to generate valuable data for improving future health risk assessments, air pollution modelling, and emission mitigation strategies where the long-term goal is to improve the public health.

Project members:
Ioannis Sadiktsis (Principal Investigator), MMK, Stockholm University
Joakim Pagels, Ergonomics and Aerosol Technology, Lund University

Past research projects

Screening of potentially toxic compounds and total toxicity of PM10 aerosols
Naturvårdsverket (Miljögiftssamordning), 2019–2020.