Research | Press release

Snowmobile safaris expose participants to unexpectedly high levels of exhaust emissions

Published on 6.11.2026

Tampere University

Letka moottorikelkkoja safarilla lumisella pellolla.

Photo: Adobe Stcok

Participants in recreational snowmobile and all-terrain vehicle (ATV) safaris may be exposed to extremely high levels of combustion-derived nanoparticles, according to a recent study by researchers at Tampere University and the University of Eastern Finland. Based on the measurements, exposure levels may at times be several times higher than those measured in busy urban areas.

The researchers measured participants’ exposure during two commercial safaris in Central Finland, an ATV tour in October 2022 and a snowmobile tour in January 2024. The study did not examine the effect of engine type on particle emissions. The highest exposure levels were recorded when the vehicles travelled in convoy formation, with riders at the rear of the group breathing exhaust emissions from the vehicles ahead.

During the safaris, particulate concentrations in the riders’ breathing zones repeatedly exceeded the typical background levels recorded in remote areas of Finland (5 μm²/cm³), occasionally rising above 1,000 μm²/cm³.

“Many people take part in safaris specifically to enjoy pristine natural environments and fresh air. However, our findings show that these activities can create a significant local air quality issue for the participants,” says Professor Santtu Mikkonen of the University of Eastern Finland (UEF).

Highest particulate concentrations recorded during snowmobiling

Snowmobile tours resulted in significantly higher exposure levels than ATV tours. According to the researchers, this may be due to snowmobile engine technology, the formation of particles in sub-zero temperatures and the spacing between vehicles.

Surprisingly, the highest exposure peaks were not recorded during idling but while riders were travelling at speed across open terrain, such as frozen lakes. The airflow generated by moving vehicles may carry nanoparticles directly into the breathing zones of riders travelling behind.

“Exposure is not limited to riders at the rear of the convoy. Even a single vehicle ahead can substantially reduce air quality in the breathing zone of the following rider,” says Associate Professor Panu Karjalainen of Tampere University.

According to the researchers, those at greatest risk are safari guides and other workers who use snowmobiles and ATVs on a daily basis, for example, in the tourism industry, reindeer husbandry, agriculture and forestry.

The study focused especially on lung-deposited surface area (LDSA), which measures the total surface area of particles that penetrate deep into the lungs. LDSA is increasingly recognised as an important indicator of the potential health effects of air pollution. The researchers note that current occupational health and safety regulations, which are primarily based on particle mass, may not fully capture the risks associated with particle exposure.

Electrification and after-treatment systems would reduce exposure

According to the researchers, electric snowmobiles and ATVs would offer the most effective means for reducing exposure to harmful nanoparticles. In the short term, exposure could be reduced through the use of advanced exhaust after-treatment systems and protective masks worn by both recreational users and workers who operate these vehicles.

“Nature tourism is based on the appeal of untouched destinations. Delivering on this promise from the perspective of air quality requires both technological advances and practical measures to minimise exposure,” says Mikkonen.

Although the study covered only a single safari location and included a limited number of measurements, the results have broader relevance. Off-road safaris can generate nanoparticle concentrations that are comparable to those found in the most polluted urban environments. The researchers say the findings underline the need to assess the air quality impacts of motorised nature tourism not only in Finland but also internationally.

The study was funded by the Jane and Aatos Erkko Foundation and conducted within the Atmosphere and Climate Competence Center (ACCC), one of the Finnish Flagships selected by the Research Council of Finland.

The study was published as a Perspective article in Environmental Research Communications under the title High Exhaust Nanoparticle Exposure during Recreational Snowmobile and All-Terrain Vehicle Safaris.