Stated benefits from urban afforestation in an arid city: a contingent valuation in Mexicali, Baja California, Mexico

The pervasiveness of particulate matter in arid cities has yet to be discussed and tackled. Given that urban trees have been documented to provide air-filtering and dry deposition services, this study documents the stated benefits from an urban afforestation scenario in Mexicali –an arid city located northwest Mexico at the US-Mexico border. Our doublebounded dichotomous contingent valuation protocol yields an estimated average annual willingness to pay (WTP) of USD 88 per household. Variations in the WTP are associated with perception of air quality and presence of respiratory symptoms in the respondent’s household. The smallest WTP (USD 75) is reported by respondents perceiving poor air quality in their neighborhood and with no household members affected by respiratory symptoms. In contrast, respondents perceiving good air quality and with at least one household member facing respiratory symptoms reported a WTP of USD 99. The average stated benefits represent around 0.8% of the annual household income

Assessing the Influence of Socioeconomic Status and Air Pollution Levels on the Public Perception of Local Air Quality in a Mexico-US Border City

Air pollution in developing countries is a growing concern. It is associated with urbanization and social and economic structures. The understanding of how social factors can influence the perception and the potential impact of air pollution have not been addressed sufficiently. This paper addresses the social vulnerability and exposure to PM10 association and its influence on the air quality perception of residents in Mexicali, a Mexico–US border city. This study used individual variables and population census data, as well as statistical and spatial analyses. A cluster of socially vulnerable populations with high exposure to coarse particulate matter (PM10) was found in the city’s peripheral areas. The spatial distribution of the local perception of air quality varied by the exposure zones of the estimated PM10 concentrations. Respondents living in very high exposure areas perceive air quality as “poor,” contrarily to a worse perception in areas of intermediate and lower exposure to PM10. Proximity to stationary sources of pollution was associated with a poor perception of air quality. Results also indicate that low household income and poor air quality perceived at the place of residence negatively influences the perceived changes in the air quality over time. The knowledge of chronic health effects related to air pollution was scarce in the sampled population, especially in the areas with very high exposure and high social vulnerability. These findings can serve as a support in local air quality management