RESUMEN
Air pollution is a worldwide health problem, and exposure to the pollution can cause damage to the human body, especially to the respiratory and cardiovascular systems. Asthma is the third most common chronic disease in Brazil, presenting high prevalence in some areas. The aim of this study was to evaluate the self-report the prevalence of asthma symptoms in Santos city, Brazil, and its associated factors in the adult population (between 18 and 59 years old). A cross-sectional study was applied in two different areas of the city. The participants of this study were selected by zip code estimated on a random sample. The ECHRS and a demographic questionnaire were used to collect data. Associations between categorical variables were tested using Pearson's chi-square test or Fisher's exact test. Single and multiple logistic regression models were applied to evaluate the risk factors for asthma. Georeferencing was implemented to distribute the cases. The highest prevalence of asthma was found in Ponta da Praia neighborhood (16.4%; p=0.019), as well as waking up with a coughing crisis in the last 12 months (26.4%; p <0.001). The risk factors for asthma were the following: living next Santos Port area (OR: 2.90; 95%CI 1.13-7.44); and the presence of O3 (OR = 2.63; 95%CI 0.86-7.96). This pioneering study demonstrated that living near the port area increases the chances of adults having self-reported asthma symptoms.