ISSN: 2455-488X
Journal of Civil Engineering and Environmental Sciences
Short Communication       Open Access      Peer-Reviewed

Ambient Temperature and the Air Quality Health Index

Mieczysław Szyszkowicz

Population Studies Division, Health Canada, Ottawa, ON, 101 Tunney’s Pasture, K1A 0K9, Canada
*Corresponding author: Mieczysław Szyszkowicz, Population Studies Division, Health Canada, Ottawa, ON, 101 Tunney’s Pasture, K1A 0K9, Canada, Tel: + (613) 762-1830; E-Mail:
Accepted: 16 March, 2017 | Received: 28 March, 2017 | Published: 30 March, 2017

Cite this as

Szyszkowicz M (2017) Ambient Temperature and the Air Quality Health Index. J Civil Eng Environ Sci 3(1): 006-007. DOI: 10.17352/2455-488X.000013

Short Communication

The Air Quality Health Index (AQHI) [1] was introduced in Canada to represent a summary measure of ambient air pollution and air health effects. The AQHI is primarily applied to inform the Canadian public of health risks associated with ambient air pollution. It is used as a scaled indicator of the environmental health risk.

The AQHI is calculated hourly based on a formula that uses the rolling three-hour average concentration levels of three air pollutants. These are the gases: ozone (O3) at ground level, nitrogen dioxide (NO2), and particulate matter (PM2.5 - particles of air pollutants with a diameter of 2.5 micrometers or less). The formula used to calculate the index is as follows:

AQHI=(100*10/10.4)*(exp(0.000537*[O3])+exp(0.000487*[PM2.5]) + exp(0.000871*[NO2]) - 3)

The AQHI value is defined based on the relative risk of mortality associated with these three air pollutants. The coefficients in the above formula were estimated using the relation between acute increases in air pollution and associations with increased risk of death as determined using data from major cities across Canada [1].

Various combinations of air pollutants were realized to determine such indices[2]. In China, the index is based on PM10 (particles of air pollutants with a diameter not greater than 10 micrometers) and NO2 [3,4]; the Russian index incorporates formaldehyde, carbon monoxide (CO) and total suspended particles (TSP) [5]. Air pollutants such as PM10, sulphur dioxide (SO2) and NO2 are used in the European regional index [6].

The values of the AQHI are reported hourly on a scale of 1 – 10+. The AQHI provides air quality and health risk information using only a single number. Its values on web pages are often represented by colours ranging from light blue (1, no risk) to dark brown (10+, very high risk). The values can be used to implement health protective behaviours (reduce and/or change and/or reschedule outdoor activity) and decrease exposure to ambient air pollution.

In this study the AQHI values were determined independently of those officially communicated. Using the above formula and hourly measurements of three ambient air pollutants, the values of the index were calculated. Thus, for each day, we have 24 index values. The daily level can be represented by the daily average, maximum or other statistical value based on the 24 hourly indices. In this work we used the daily maximum to represent the value of the index. The main goal of this work is to investigate the relations between the index and ambient air temperature in two locations in Canada.

We used the data from two cities in Canada: Windsor (Ontario) and Edmonton (Alberta). Edmonton data are for the period from April 17, 1998 to March 31, 2002. Windsor data are for the period from April 1, 2004 to December 31, 2011. Table 1 summarizes the estimated values in both cities.

As we see from the table, the statistical characteristics of the AQHI are very comparable for both cities. We only observe large difference for temperature. For a simple analysis and comparison, we simply created a scatter plot to illustrate the relations between temperature and the AQHI values. To stabilize the variations and to simplify the plot, the temperature was grouped in bins of 5o C width.

Both figures indicate that the AQHI has a tendency to increase with temperature. It suggests that around 15o C and higher the index increases its value. This increase can be related to levels of ground ozone. As the AQHI is based only on three air pollutants, it also reflects seasonal changes in their levels [7,8].

There are a few publications which used the AQHI as an exposure/risk measure in relation to various health outcomes [9-15]. We conclude that the estimated higher values on hot days might also have preventive effects on temperature health impacts.

  1. Stieb DM, Burnett RT, Smith-Doiron M, Brion O, Shin HH, et al. (2008) A new multipollutant, no-threshold air quality health index based on short-term associations observed in daily time-series analyses. J Air Waste Manag Assoc 58: 435-450. Link:
  2. Szyszkowicz M. (2015) an approach to represent a combined exposure to air pollution. Int J Occup Med Environ Health 28: 823-830. Link:
  3. Chen RJ, Wang X, Meng X, Hua J, Zhou Z, et al. (2013) Communicating air pollution-related health risks to the public: An application of the Air Quality Health Index in Shanghai, China. Environment International 51: 168-173. Link:
  4. Li X, Xiao J, Lin H, Liu T, Qian Z, et al. (2017) the construction and validity analysis of AQHI based on mortality risk: A case study in Guangzhou, China. Environ Pollut 220: 487-494. Link:
  5. Khripach LV, Novikov SM, Zykova IE, Fedoseeva VN, Zhelezniak EV, et al. (2012) Testing of the system of Biochemical and Immunological indices of the state of population health in the survey of residents of Moscow exposed to ambient air pollution. Gigiena i Sanitariya 5: 30-34. Link:
  6. Sicard P, Talbot CLM, Lesne O, Antoine M, Nicolas A, et al. (2012) The Aggregate Risk Index: An intuitive tool providing the health risks of air pollution to health care community and public. Atmospheric Environment 46: 11-16. Link:
  7. Robichaud A, Ménard R, Zaïtseva Y, Anselmo D (2016) Multi-pollutant surface objective analyses and mapping of air quality health index over North America. Air Qual Atmos Health 9: 743-759. Link:
  8. Weerasinghe S (2017) Statistical modeling of complex health outcomes and air pollution data: Application of air quality health indexing for asthma risk assessment. Epidemiology Biostatistics and Public Health 14: 1. Link:
  9. Abelsohn A, Stieb DM (2011) Health effects of outdoor air pollution Approach to counseling patients using the Air Quality Health Index. Canadian Family Physician 57: 881-887. Link:
  10. To T, Shen S, Atenafu EG, Guan J, McLimont S, et al. (2013) The air quality health index and asthma morbidity: A population-based study. Environmental Health Perspective 121: 46-52 Link:
  11. Szyszkowicz M, Kousha T (2014) Emergency department visits for asthma in relation to the Air Quality Health Index: a case-crossover study in Windsor, Canada. Can J Public Health 105: 336-341. Link:
  12. Kousha T, Valacchi G (2015) the air quality health index and emergency department visits for urticaria in Windsor, Canada. J Toxicol Environ Health A 78: 524-533. Link:
  13. Kousha T, Castner J (2016) the Air Quality Health Index and Emergency Department Visits for Otitis Media. J Nurs Scholarsh 48: 163-171. Link:
  14. Chen L, Villeneuve PJ, Rowe BH, Liu L, Stieb DM (2014) The Air Quality Health Index as a predictor of emergency department visits for ischemic stroke in Edmonton, Canada. J Expo Sci Environ Epidemiol 24: 358-364. Link:
  15. Xiao Q, Yang Liu Y, Mulholland JA, Russell AG, Darrow LA, et al. (2016) Pediatric emergency department visits and ambient Air pollution in the U.S. State of Georgia: a case-crossover study. Environ Health 15: 115. Link:
© 2017 Szyszkowicz M. This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.

Help ?