Molecular composition of fresh and aged aerosols from residential wood combustion and gasoline car with modern emission mitigation technology.

Emissions from road traffic and residential heating contribute to urban air pollution. Advances in emission reduction technologies may alter the composition of emissions and affect their fate during atmospheric processing. Here, emissions of a gasoline car and a wood stove, both equipped with modern emission mitigation technology, were photochemically aged in an oxidation flow reactor to the equivalent of one to five days of photochemical aging. Fresh and aged exhausts were analyzed by ultrahigh resolution mass spectrometry. The gasoline car equipped with a three-way catalyst and a gasoline particle filter emitted minor primary fine particulate matter (PM2.5), but aging led to formation of particulate low-volatile, oxygenated and highly nitrogen-containing compounds, formed from volatile organic compounds (VOCs) and gases incl. NOx, SO2, and NH3. Reduction of the particle concentration was also observed for the application of an electrostatic precipitator with residential wood combustion but with no significant effect on the chemical composition of PM2.5. Comparing the effect of short and medium photochemical exposures on PM2.5 of both emission sources indicates a similar trend for formation of new organic compounds with increased carbon oxidation state and nitrogen content. The overall bulk compositions of the studied emission exhausts became more similar by aging, with many newly formed elemental compositions being shared. However, the presence of particulate matter in wood combustion results in differences in the molecular properties of secondary particles, as some compounds were preserved during aging.

Chemical Fingerprinting of Biomass Burning Organic Aerosols from Sugar Cane Combustion: Complementary Findings from Field and Laboratory Studies.

Agricultural fires are a major source of biomass-burning organic aerosols (BBOAs) with impacts on health, the environment, and climate. In this study, globally relevant BBOA emissions from the combustion of sugar cane in both field and laboratory experiments were analyzed using comprehensive two-dimensional gas chromatography time-of-flight mass spectrometry. The derived chemical fingerprints of fresh emissions were evaluated using targeted and nontargeted evaluation approaches. The open-field sugar cane burning experiments revealed the high chemical complexity of combustion emissions, including compounds derived from the pyrolysis of (hemi)cellulose, lignin, and further biomass, such as pyridine and oxime derivatives, methoxyphenols, and methoxybenzenes, as well as triterpenoids. In comparison, laboratory experiments could only partially model the complexity of real combustion events. Our results showed high variability between the conducted field and laboratory experiments, which we, among others, discuss in terms of differences in combustion conditions, fuel composition, and atmospheric processing. We conclude that both field and laboratory studies have their merits and should be applied complementarily. While field studies under real-world conditions are essential to assess the general impact on air quality, climate, and environment, laboratory studies are better suited to investigate specific emissions of different biomass types under controlled conditions.

[Allergies in the light of global environmental changes]. / Allergien im Lichte globaler Umweltveränderungen.

BACKGROUND: The increase in allergies began worldwide with the onset of the Great Acceleration. Environmental pollution and climate change now threaten to cancel out decades of success in health research. OBJECTIVE: A summary of environmental influences is provided, which not only shows the significant increase in the prevalence of allergies worldwide but also that of noncommunicable diseases. The effects of the climate crisis on allergies and the multifactorial and interfunctional relationships with other environmental changes are described in detail. MATERIAL AND METHODS: In order to obtain an overview of the possible effects of global environmental changes on allergies, a wide range of literature was evaluated and the study results were prepared and summarized. RESULTS: A large number of allergens are influencing the human exposome on a daily basis. These allergens are triggered by environmental changes, such as air pollution in the ambient air and indoors, chemicals in everyday objects or residues in food. People are sensitized by the interaction of allergens and pollutants. CONCLUSION: The prevalence of allergies is stagnating in industrialized countries. This is probably just the calm before the storm. The accelerating effects of global warming could make pollen and air pollutants even more aggressive in the future. Urgent action is therefore needed to minimize environmental pollution and mitigate climate change.