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A new method for determination of relative contribution of aerosol sources to the oxidative potential of PM

A new method for determination of relative contribution of aerosol sources to the oxidative potential of PM

Exposure to combustion-derived air pollution aerosols has been shown to have many adverse effects on human health, including the impact of cellular oxidative stress. In this toxicological study we developed a new method to assess the contribution of different sources of ambient aerosols to the oxidative potential (OP) of particulate mass (PM), using a long time series of PM10 samples.

The OP was measured on filter samples collected over a full year in the Alpine valley city of Chamonix (France), using two OP protocols: ascorbic acid (AA) and dithiothreitol (DTT) assays. We used PMF analysis from an advanced source-receptor model to obtain source apportionment, and inverted the OP measurements in order to attribute both an intrinsic OP to the sources and the evolution of the source contributions to OPs over the year.

Our results highlight the importance of both biomass burning and vehicular sources as the major contributors to OP in both assay methods. Significant differences were observed between the DTT and AA protocols. This emphasizes the chemical specificities of these tests and the need for a standardized approach for future studies of the epidemiology or toxicology of PM.

The article was published in Atmospheric Chemistry and Physics:
An apportionment method for the oxidative potential of atmospheric particulate matter sources: application to a one-year study in Chamonix, France

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Comparison of a traffic emissions model with measurements in a European city

Comparison of a traffic emissions model with measurements in a European city

Dr. Irena Ježek of the Aerosol R&D team just published a scientific paper in the prestigious journal Atmospheric Environment titled: “The traffic emission-dispersion model for a Central-European city agrees with measured black carbon apportioned to traffic”. This scientific paper presents a simple methodology for modeling traffic emissions using real world emission factors. Using real-world emission factors in the model is essential, to make the emissions representative of the actual in-use fleet. This is the only way in which emission reduction strategies can be planned, that target vehicles that pollute the most.

The research shows how an improved understanding of traffic emissions and impacts, can lead to improved management and legislative controls. The model’s results were verified with in-situ measurements of Black Carbon apportioned to traffic with the Aethalometer model, and showed excellent agreement. The most efficient emission reduction scenarios were those where the highest polluting vehicles were targeted. Removing 10% of the highest polluting vehicles would reduce BC concentrations in the city center by 39%, and NOx by 33%.

We would like to thank Suzana Pranjc and the Office of Utility, Transport and Spatial Planning of the Municipality of Maribor; the Slovenian Ministry of Infrastructure; the Slovenian Environment Agency; and the Slovenian National Laboratory of Health, Environment and Food; for contributing data to the analyses presented in this pubclication.

This research was supported by the European Social Foundation, (SPIRIT), contract no. P-MR-10/04.

The traffic emission-dispersion model for a Central-European city agrees with measured black carbon apportioned to traffic
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THE “THIRD POLE” IS MELTING

THE “THIRD POLE” IS MELTING

Aerosol taking part in ground breaking measurements 7 km above Mt. Everest

The Tibetan Plateau of China is a critical element of the planetary environment. Its influence on global climate had led to its description as the “Third Pole”.

The snow and ice cover of this region in winter-time has a global effect on patterns of long-range atmospheric circulation. Rivers originating in this region flow through, and provide water to, areas containing one-quarter of the world’s population. This region is currently facing a serious problem from high concentrations of pollution, including aerosol particles of “smoke”, which are transported onto the Tibetan Plateau from adjacent areas with high population density and strong emissions. These aerosols can directly impact the ecosystem and vegetation: but more seriously, the darkening of snow and ice can lead to premature thawing and the disappearance of glaciers.

To determine the sources and effects of this pollution, measurements of aerosol particles are essential and necessary. The Institute of Tibetan Plateau Research of the Chinese Academy of Sciences has been measuring aerosols at ground-based monitoring sites across the region for several years. This work will now be expanded to study the atmosphere above the surface using a tethered balloon carrying instruments to measure the flow of pollutants from distant regions. The ground-level measurements, including a station at the Base Camp of Mt. Everest, use Aethalometer ® equipment developed by Aerosol d.o.o. The balloon profiling will use a unique research variant of this instrument, developed in Ljubljana.

The first series of research flights will be performed in May 2018 in the vicinity of Mount Everest. The Chinese research balloon will fly up to an altitude of 15 km above sea level. Data will be transmitted to the ground in real time, to allow the balloon operators to optimize the flying conditions. Dr. Matjaž Kobal, Head of R&D at Aerosol, will participate in the Mt. Everest balloon flight research program to operate the equipment and to analyze the data.

Instruments made by Aerosol have been already installed at the South Pole, Kashmir, Greenland, the Amazonian rainforest, and almost everywhere else. Our equipment is designed to perform exceptionally well even in the most demanding environments.

The “Tibetan Plateau Balloon Project” will generate ground breaking scientific data to support fundamental research into global pollution and climate change; and will help to support public policy decisions to improve air quality and water security for one-quarter of the global population. It will also foster further collaboration in areas of research, technology, education and science between Aerosol d.o.o. and the Chinese Academy of Science; and between Slovenia and China.

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Five Reasons to Measure Black Carbon

Five Reasons to Measure Black Carbon

If we would need to sum up the main reasons why Black Carbon needs to be measured, these would be 5 most important ones.

  1. Black Carbon is a primary aerosol component of Diesel Particulate Matter, a known toxin and regulated pollutant by several regulatory agencies, including the California Air Resources Board (CARB).
  2. Diesel Particulate Matter is known to cause adverse health effects in people who are exposed, including premature hospitalization, asthma attacks, bronchitis, other respiratory and cardiovascular symptoms, and premature death.
  3. Black Carbon is the second leading cause of Global Warming.
  4. Black Carbon is emitted as a primary pollutant to the atmosphere through a variety of incomplete combustion of sources and fuels; BC concentration cannot be modeled or predicted, it must be measured.
  5. Black Carbon is NOT adequately characterized through PM-2.5 mass only measurements, chemical speciation is necessary.

Magee Scientific is the originator of the Aethalometer®, the most-widely-used instrument for the real-time measurement of Black Carbon aerosol particles in the atmosphere. We measure it, so you can take action. More about Aethalometer®

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