Particulate matter in air at indoor go-kart facilities in Bavaria, Germany

Indoor go-karting is a popular free time activity for many people, including adults and children. Particulate matter from engine emissions, brake and tire debris and gaseous pollutants are important sources of air pollution. Exposure to these air pollutants is associated with health-related problems. In this study, the exposure of employees and spectators to particulate matter was measured in 8 indoor go-kart facilities (6 facilities used gasoline, one used liquid gas and one used electricity for their go-karts). The mass concentrations of particulate matter were continuously analyzed. Particles were sampled and analyzed by inductively coupled plasma mass spectrometry and electron microscopy coupled with energy-dispersive X-ray spectroscopy. The mean PM10 concentrations ranged between 4.9 and 34.9 μg/m³ for workplaces and 5.6 and 28.4 μg/m³ for spectator areas. The mean PM2.5 concentrations measured in workplaces ranged from 2.3 to 29.2 μg/m³ and from 2.4 to 27.4 μg/m³ in the spectator areas. The highest PM10 and PM2.5 concentrations were measured at the liquid gas go-kart facility and at go-kart facilities with the maximum number of go-karts running simultaneously. The electric go-kart facility showed high PM10 concentrations but low PM2.5 values. The highest particle number concentration was measured in the workplace of the facility using liquid gas go-karts (2.7 × 105 particles/cm³), and the lowest concentration at both measurement points of the electrical go-kart facility (1.8 × 104 particles/cm³). Metals such as copper, zinc, strontium, barium, aluminum, calcium, manganese, iron and nickel were found in nearly all samples with help of inductively coupled plasma mass spectrometry. The most abundant metal was iron, with concentrations up to 5.6 μg/m3 (electric go-kart facility). Electron microscopic investigations showed high concentrations of soot in all samples, except for the samples of the electric go-kart facility. Additionally, agglomerates with iron and other metals were found in all samples. To summarize, electric go-karts, combined with a good ventilation system, seem to be more suitable for indoor use.