Different exposures to pollutants because of job/home different locations


(Bayat) #1

Hi,
In studies that have been done so far, the exposure to pollutants has been calculated for the resident population. While a significant part of the day, the spatial distribution of the population varies with the distribution of the resident population, and thus the exposure levels of individuals with air pollutants are not calculated correctly.

For example, Tehran has more than 8.7 million inhabitants, spread over 700 square kilometers. At the start of every day, a population of about 2 million people from nearby cities come to Tehran to work in the city for more than eight hours. The job locations of most residents are also different from their home locations. So, the distribution of the population of the day and night in Tehran is very different. The distribution of particulate matter is also different in different parts of the city.

How BenMAP-CE can consider these population distribution differences in calculating health benefits of reducing PM2.5 concentrations?

Thank you,


(Juan J. Castillo) #2

Hi Bayat, I found this to be a very interesting question. Defining the exposure is usually challenging because exposure actually changes through the day based on the activities. Generally people live in one place and work in a different one so thy have two levels of exposure in addition to variations due to commute and transportation. In terms of work-related exposure, it is documented that they are some jobs that have higher exposure and risks than others. mainly those who do work on outdoor environments in polluted cities.

With that said, when doing a health impact assessment for a city, we are usually focused on the overall effects over the population. What we have done in other cities is using the place of residence as the unit of analysis, we do this for two main reasons: 1) because the most vulnerable population (children and the elderly) spent most of their time at home or nearby; and 2) because even if working, people in our areas of analysis tend to spend more time in home than at work. Clearly that can change from place to place.

Is it possible for you to expand you area of analysis so you can include the population living in the adjacent cities? One advantage of doing that, from a policy point of view is that you can aim to develop abatement strategies with a metropolitan/regional approach so cities can be aware that this is not just a Tehran issue but that they are being affected too.