Investigating the industrial origin of terpenoids in a coastal city in northern France: A source apportionment combining anthropogenic, biogenic, and oxygenated VOC.

Terpenoids have long been known to originate from natural sources. However, there is growing evidence for emissions from anthropogenic activities in cities, in particular from the production, manufacturing, and use of household solvents. Here, as part of the DATAbASE (Do Anthropogenic Terpenoids mAtter in AtmoSpheric chEmistry?) project, we investigate for the first time the potential role of industrial activities on the terpenoid burden in the urban atmosphere. This study is based on continuous VOC observations from an intensive field campaign conducted in July 2014 at an industrial-urban background site located in Dunkirk, Northern France. More than 80 VOCs including oxygenated and terpenoid compounds were measured by on-line Thermal Desorption Gas Chromatography with a Flame Ionization Detection (TD-GC-FID) and Proton Transfer Reaction-Time of Flight Mass Spectrometry (PTR-ToFMS). Isoprene, α-pinene, limonene and the sum of monoterpenes were the terpenoids detected at average mixing ratios of 0.02 ± 0.02 ppbv, 0.02 ± 0.02 ppbv, 0.01 ± 0.01 ppbv and 0.03 ± 0.05 ppbv, respectively. Like other anthropogenic VOCs, the mixing ratios of terpenoids significantly increase downwind the industrial plumes by one order of magnitude. Positive Matrix Factorization (PMF) was performed to identify the different emission sources of VOCs and their contribution. Six factors out of the eight factors extracted (r2 = 0.95) are related to industrial emissions such as solvent use, chemical and agrochemical storage, metallurgy, petrochemical, and coal-fired industrial activities. From the correlations between the industrial-type PMF factors, sulfur dioxide, and terpenoids, we determined their emissions ratios and we quantified for the first time their industrial emissions. The highest emission ratio is related to the alkene-dominated factor and is related to petrochemical, metallurgical and coal-fired industrial activities. The industrial emissions of monoterpenes equal 8.1 ± 4.3 tons/year. Those emissions are as significant as the non-industrialized anthropogenic ones estimated for the Paris megacity.

Overview of the Alaskan Layered Pollution and Chemical Analysis (ALPACA) Field Experiment.

The Alaskan Layered Pollution And Chemical Analysis (ALPACA) field experiment was a collaborative study designed to improve understanding of pollution sources and chemical processes during winter (cold climate and low-photochemical activity), to investigate indoor pollution, and to study dispersion of pollution as affected by frequent temperature inversions. A number of the research goals were motivated by questions raised by residents of Fairbanks, Alaska, where the study was held. This paper describes the measurement strategies and the conditions encountered during the January and February 2022 field experiment, and reports early examples of how the measurements addressed research goals, particularly those of interest to the residents. Outdoor air measurements showed high concentrations of particulate matter and pollutant gases including volatile organic carbon species. During pollution events, low winds and extremely stable atmospheric conditions trapped pollution below 73 m, an extremely shallow vertical scale. Tethered-balloon-based measurements intercepted plumes aloft, which were associated with power plant point sources through transport modeling. Because cold climate residents spend much of their time indoors, the study included an indoor air quality component, where measurements were made inside and outside a house to study infiltration and indoor sources. In the absence of indoor activities such as cooking and/or heating with a pellet stove, indoor particulate matter concentrations were lower than outdoors; however, cooking and pellet stove burns often caused higher indoor particulate matter concentrations than outdoors. The mass-normalized particulate matter oxidative potential, a health-relevant property measured here by the reactivity with dithiothreiol, of indoor particles varied by source, with cooking particles having less oxidative potential per mass than pellet stove particles.

Investigation on the near-field evolution of industrial plumes from metalworking activities.

In a context where a significant fraction of the population lives near industrial areas, the main objectives of this study are to provide (a) new data on PM2.5 chemical compositions, heavy-metal concentrations and trace gases released by metalworking activities and (b) new information on the near-field evolution (up to about a thousand meters) of such industrial plumes in terms of particle chemical composition and size distribution. For that purpose, a one-month field campaign was performed in an industrial area near the city of Dunkirk (Northern France), combining measurements of atmospheric dynamics and physico-chemical characterization of air masses. Comparisons between several elemental ratios (mainly Mn/Fe), particle size distributions and volatile organic compound (VOC) concentrations at the stacks and at a near-field site suggest that plumes of a ferromanganese alloy plant were quickly mixed with pollutants emitted by other sources (mainly other industries, possibly traffic and sea spray), in particular a neighboring steelworks, before reaching the sampling site. This led to the emergence of secondary particles related to condensation and/or aggregation phenomena inside the plumes. Metalworking emissions were also identified as a source of new particle formation, formed through the emission of gaseous precursors and their fast transformation and condensation, over a timescale of minutes before reaching the near-field site 800 m downwind. Ultrafine particles emitted at the stacks also quickly agglomerated to form larger particles before reaching the near-field site. These results show that, even over short distances, the chemical composition and size distribution of metalworking plumes may evolve rapidly and the characteristics of particles at the boundary of an industrial area (especially in contiguous urban areas) may differ from those emitted directly at the stacks.

Development of a methodology examining the behaviours of VOCs source apportionment with micro-meteorology analysis in an urban and industrial area.

During summer 2009, online measurements of 25 Volatile Organic Compounds (VOCs) from C6 to C10 as well as micro-meteorological parameters were simultaneously performed in the industrial city of Dunkerque. With the obtained data set, we developed a methodology to examine how the contributions of different source categories depend on atmospheric turbulences, and the results provided identification of emission modes. Eight factors were resolved by using Positive Matrix Factorization model and three of them were associated with mixed sources. The observed behaviours of contributions with turbulences lead to attribute some factors with sources at ground level, and some other factors with sources in the upper part of surface layer. The impact of vertical turbulence on the pollutant dispersion is also affected by the distance between sources and receptor site.

Fast changes in chemical composition and size distribution of fine particles during the near-field transport of industrial plumes.

Aerosol sampling was performed inside the chimneys and in the close environment of a FeMn alloys manufacturing plant. The number size distributions show a higher abundance of ultrafine aerosols (10-100 nm) inside the plume than upwind of the plant, indicating the emissions of nanoparticles by the industrial process. Individual analysis of particles collected inside the plume shows a high proportion of metal bearing particles (Mn-/Fe-) consisting essentially of internally mixed aluminosilicate and metallic compounds. These particles evolve rapidly (in a few minutes) after emission by adsorption of VOC gas and sulfuric acid emitted by the plant but also by agglomeration with pre-existing particles. At the moment, municipalities require a monitoring of industrial emissions inside the chimneys from manufacturers. However those measures are insufficient to report such rapid changes in chemical composition and thus to evaluate the real impact of industrial plumes in the close environment of plants (when those particles leave the industrial site). Consequently, environmental authorities will have to consider such fast evolutions and then to adapt future regulations on air pollution sources.