PM2.5 and Ozone only slightly reduced during the COVID lockdown in China

July 29, 2020

A recent study by the University of Leeds and the Southern University of Science and Technology in Shenzhen divulged PM2.5 had only a small reduction across China and it was not lowered at all in Northeast China. The PM2.5 reduction of 11% across China was disappointing in comparison to the reduction 27% of NO2 across China.  

Lead author Ben Silver, from the University of Leeds, said: “PM2.5 particles had only a modest reduction and are the most harmful constituent of air pollution, as they travel deep into the lungs and bloodstream and damage the lungs and heart.

19 From UC Davis in Global List of Most-Cited Researchers

December 04, 2018

Nineteen researchers from the University of California, Davis, have been named in the annual Highly Cited Researchers 2018 list released by Clarivate Analytics. The list identifies exceptional scientists and social scientists who have demonstrated significant influence by publishing multiple papers that rank in the top 1 percent by citations in a particular field and year, over a 10-year period. 

Multi-wavelength analysis of particle light absorption

This project is no longer running.

AQRC scientists have designed and built a new broad-band light source instrument to adapt the Hybrid Integrating Plate/Sphere Analysis (HIPS) light absorption measurement for a full spectrum of wavelengths throughout the visible and including the near IR and UV. Work is underway to develop approaches for calibration and for analysis of the data from this new spectrometer.

Evaluation of organic carbon measurements in the IMPROVE and CSN networks

The gain and loss of gaseous carbonaceous material from quartz filters can bias the measurement of organic particulate matter. The Air Quality Research Lab scientists have worked with others in the IMPROVE and Chemical Speciation Network (CSN) communities to investigate organic carbon measurement uncertainty related to determining a consistent method for estimating sampling artifacts and evaluating post-sampling losses during field latency and transport.

FT-IR Analysis of Teflon (PTFE) Filter Samples

FT-IR is a non-destructive which allows the filter samples to be analyzed by other non-destructive methods such as gravimetric for mass, XRF for elements, HIPS for light absorption, or destructive methods such as ion chromatography for ions or GC/MS for organic compounds after FT-IR analysis. FT-IR analysis and multivariate calibrations measure TOR-equivalent OC and EC, Functional groups such as aliphatic CH, carboxylic acids, carboxylates, non-acid carbonyl and alcohol OH (carbohydrates), Inorganic ions including sulfate, nitrate and ammonium, Soil elements and PM mass.

For questions on ordering services contact Ann Dillner.

Characterization of IMPROVE data quality

Each year the Air Quality Research Center delivers nearly one million new measurement values for the IMPROVE network. A large community of researchers and analysts use these data to address a wide range of scientific and regulatory issues. All data pass through multiple layers of review and quality assurance before publication, but all carry some uncertainty from the irreducible error that is present in any measurement.


Chemical Speciation Network What It Is

CSN (Chemical Speciation Network) is a long-term national monitoring program for the EPA (Environmental Protection Agency). Created in 2000 as a response to support implementation of the 1997 PM2.5 National Ambient Air Quality Standards (NAAQS) as well as the 1999 Regional Haze Rule (regulations for states to establish goals in improving visibility), CSN is a PM2.5 sampling network with sites located principally in densely populated areas.