Day-night variability of PM10 components at a Mediterranean urban site during winter

• Published in: Air quality, atmosphere and health atmosphere and health, 2018-12, Vol.11 (10), p.1251-1258
• Main Authors: Galindo, Nuria, Yubero, Eduardo, Nicolás, Jose F., Varea, Montse, Clemente, Álvaro
• Format: Article
• Language: English
• Subjects: Aerosols; Air sampling; Atmospheric aerosols; Atmospheric Protection/Air Quality Control/Air Pollution; Carbon; Copper; Daytime; Earth and Environmental Science; Emissions; Environment; Environmental Health; Health Promotion and Disease Prevention; Ions; Laboratories; Metal concentrations; Metals; Meteorological conditions; Night; Nighttime; Nitrates; Organic carbon; Organic chemistry; Particulate matter; Pollutants; Secondary aerosols; Statistical analysis; Statistical methods; Traffic; Urban areas; Vehicle emissions; Vehicles; VOCs; Volatile organic compounds; Winter
• ISSN: 1873-9318; 1873-9326
• DOI: 10.1007/s11869-018-0627-8

Daytime and nighttime PM 10 samples were collected during winter at an urban site in Southeastern Spain. Samples were subsequently analyzed to determine the concentrations of water-soluble ions, carbonaceous species, and metals. PM 10 daytime and nighttime concentrations were 26.1 and 20.6 μg/m 3 , respectively. This difference may be mainly attributed to the reduction in the number of vehicles during nighttime. Traffic-related components such as EC, Ca and other crustal elements, Cu or Zn, showed statistically significantly higher concentrations during daytime, suggesting that traffic emissions were more relevant than day-to-night differences in meteorological conditions. In contrast, no significant differences between daytime and nighttime levels of secondary inorganic ions (SO 4 2− , NO 3 − and NH 4 + ) were found. Primary and secondary organic carbon concentrations were estimated using the EC tracer method. As expected, POC levels were greater during the day due to increased vehicle exhaust emissions; conversely, higher SOC concentrations were registered during the nighttime period. This was most likely the result of a significant contribution of nighttime chemistry to the formation of secondary organic aerosols.