AIR POLLUTANTS AND INCIDENCE OF ACUTE RESPIRATORY AND GASTRO-INTESTINAL INFECTIONS IN A CITY SITUATED ON A SEMI-ARID REGION OF NORTHWESTERN MEXICO

High concentrations of particulate matter (PM) and polluting gases in urban areas are related to anthropogenic activity. This fact is even more evident when environmental conditions, such as those characterizing arid and semi-arid zones, favor the re-suspension of PM, resulting in the incapacity of the atmosphere to clean and eliminate pollutants. The city of Hermosillo, capital of Sonora, located in northwestern Mexico, is characterized by: 1) a rapid growth and increase in the vehicular park in the last decades; 2) a lack of vehicle emission regulations; 3) import used vehicles from the USA; 4) high concentrations of PM; and 5) high incidences of respiratory and gastrointestinal diseases. The combination of all these features favors a poor air quality in the urban area of Hermosillo. The present investigation uses the 2015 data from University Network of Atmospheric Observatories (RUOA) station situated in Hermosillo, which includes concentrations of particulate matter (PM2.5 and PM10), as well as ozone, carbon monoxide, sulfur dioxide, nitrogen monoxide, nitrogen dioxide. In addition, climate data is used to evaluate the correlation of these pollutants with a database of incidences of respiratory and gastrointestinal diseases from a Hospital in Hermosillo. A principal component analyses (PCA) was carried out and the data suggest that there is an increase of respiratory diseases when the atmospheric pressure, PM and gases (SO₂, NO₂, NO, CO) are high, particularly during the period comprised between November and February. Ozone is the only gas that is not correlated with the incidence of respiratory diseases. The data also suggest that the increases of pressure, PM and gases, are inversely related to decreases in the wind speed, temperature and radiation. A third component suggest that gastrointestinal diseases are not related to none of the environmental factors, although they are inversely correlated to humidity and directly correlated to atmospheric pressure. This supports the evidence that mixtures of pollutants can affect population health, as oppose to what was previously thought in Hermosillo, that increment in particulate matter was the reason of incidence of respiratory diseases.