Air quality in indoor go-kart facilities in Germany.

Indoor go-kart driving and viewing is enjoyed by people of all ages. However, it may pose health hazards, especially for children, pregnant women, cardiovascular patients, and elderly individuals. Depending on the race length, for example, high concentrations of various contaminants may result in severe health problems. Therefore, this project investigated the Indoor Air Quality of eight indoor go-kart facilities. In general, karts that used regular fuel produced the highest concentrations of CO, benzene, TVOC, and BaP, with maximum levels up to 150 mg/m3 , 170 µg/m3 , 2690 µg/m3 , and 8.7 ng/m3 , respectively. As expected, the maximum CO concentrations at go-kart facilities that used liquid gas and electric karts (20 and <6 mg/m3 , respectively) were significantly lower than those at other facilities. The highest 95th percentile values for NO (2680 µg/m3 ) and NO2 (280 µg/m3 ) were measured for karts with liquid gas. The alkane, alkene, and cycloalkane groups, as well as benzene and the alkyl benzenes, were the predominant components of the measured TVOCs. Overall, owners of indoor go-kart tracks should ensure that the ventilation with regard to combustion products is optimally adapted in any case to reduce the levels of critical air pollutants.

Siloxane in baking moulds, emission to indoor air and migration to food during baking with an electric oven.

Linear and cyclic volatile methylsiloxanes (l-VMS and c-VMS) are man-made chemicals with no natural source. They have been widely used in cosmetics, personal care products, coatings and many other products. As a consequence of their wide use, VMS can be found in different environmental media, as well as in humans. We bought 14 new silicone baking moulds and 3 metallic moulds from the market and used them in different baking experiments. Four of the silicone baking moulds were produced in Germany, two in Italy, four in China, and for the other moulds were no information available. The metal forms were all produced in Germany. VMS were measured in the indoor air throughout the baking process and at the edge and in the center of the finished cakes using a GC/MS system. Additionally, the particle number concentration (PNC) and particle size distribution were measured in the indoor air. The highest median concentrations of VMS were observed immediately following baking: 301 µg/m3 of D7, 212 µg/m3 of D6, and 130 µg/m3 of D8. The silicone moulds containing the highest concentrations of c-VMS corresponded with distinctly higher concentrations of the compounds in indoor air. Using a mould for more than one baking cycle reduced the indoor air concentrations substantially. Samples collected from the edge of the cake had higher concentrations relative to samples from the center, with a mean initial concentration of 6.6 mg/kg of D15, 3.9 mg/kg of D9, 3.7 mg/kg of D12, and 4.8 mg/kg of D18. D3 to D5 were measured only at very low concentrations. Before starting the experiment, an average PNC of 7300 particles/cm3 was observed in the room's air, while a PNC of 140,000 particles/cm3 was observed around the electric stove while it was baking, but this PNC slowly decreased after the oven was switched off. Baking with 4 of the moulds exceeded the German indoor precaution guide value for c-VMS, but the health hazard guide value was not reached during every experiment. Compared to other exposure routes, c-VMS contamination of cake from silicone moulds seems to be low, as demonstrated by the low concentrations of D4 and D6 measured. For less volatile c-VMS > D6 the results of the study indicate that food might play a more important role for daily intake. As a general rule, silicone moulds should be used only after precleaning and while strictly following the temperature suggestions of the producers.

Physicochemical characterization of aerosol particles emitted by electrical appliances.

Adverse health effects of airborne particulate matter depend on parameters like particle size, particle surface and chemical composition. Major emission of indoor particles is caused by combustion processes like tobacco smoking and cooking. Nevertheless, the use of household electrical appliances, such as vacuum cleaners, flat irons or hair dryers, can produce particles as well. In this study the emissions of different hair dryers and flat irons were investigated using a test chamber. The particle number concentrations, particle volume concentrations, as well as the size distributions were measured. Particles were sampled and analyzed by electron microscopy, inductively coupled plasma mass spectrometry and gas chromatography mass spectrometry. Moreover different volatile organic compounds (VOCs) were measured. Each tested appliance, especially flat irons produced small particles with diameters far below 100nm and might be a nonnegligible source for indoor particles. Copper was the main identified element in most of the particles emitted from hair dryers, but in the emission of two hair dryers silver-containing nanoparticles were found as well. Various VOCs were observed in the emission of both flat irons and hair dryers, while cyclic siloxanes were detected only in the emission of flat irons. The use of flat irons or hair dryers may significantly contribute to the personal particle exposure.