Stroke is one of the major causes of worldwide deaths, difficult to treat and recover from patients 1. In more severe cases this illness can lead to physical and mental disabilities, which harms the lifestyle of many individuals 2.
Besides, stroke damage may continue even during treatment, because of the encephalic white matter degeneration 3. This creates an obstacle for rehabilitation, which can be an important factor for people in financial difficulties, on account of its high costs or even labor problems 4.
In this context, the study of some environmental factors, which leads to an increase of stroke incidence, is important because the treatment and prevention of this morbidity are more effective in a risk control scenario 5. Moreover, the treatment methods of stroke are precarious in many Brazilian areas, fluctuating a lot even in the same town 6.
Environmental factors have great impact on population heath, being that air pollution was associated with at least 5.708.000 deaths all over the world in 2015 7. These characteristics surround all the individuals and affects the type of work produced by each person daily, so the quality of life is closely related to the ambient8.
The atmospheric pollution, temperature and air humidity, already have been associated with stroke risk 9-11. This can corroborate the increase in cases of stroke in those regions12. Therefore, despite the fact that stroke incidence has been falling in Brazilian Southeast in the period from 2008 to 2012 13, the numbers of death by this disease is increasing due to population rises and epidemiology transition in the country 14.
The residing population in São Paulo, a global metropole is influenced by air pollution and climate changes, due to the accumulation of pollutants in this place by vehicular traffic and industrial gases emitted in the region 15
Stroke, as already seen, has high rates of mortality and high incidence worldwide 16, as in Brazil. The relationship of this disease with pollution and temperature has already been considered in other studies 17,19. However, in 2016, the city of São Paulo experienced high pollutant rates in addition to very high or very cold temperatures for national standards. This has raised doubts about how these environmental variables can affect the incidence of hospital admissions for stroke in a large global metropolis.
Thus, the main objective of this article is to analyze the association between ambient temperature, air humidity and atmospheric pollution with the incidence of Stroke in the city of São Paulo, Brazil, in 2016.