Introduction
It is known that air pollution had adverse effects on the health of those exposed to it. There is a diverse mix of air pollutants and the most common pollutants in outdoor air include carbon monoxide (CO), nitrogen oxides (NOx), sulfur dioxide (SO2), ground level ozone and particulate matter (PM) (1). Outdoor air pollution is a mixture of gases and particulate matter (PM) of varying sizes and it is often difficult to isolate the source of the PM from all the possible sources of combustion (1). Traffic-related air pollution (TRAP) is a significant contributor to air pollution in urban areas and motor vehicles release a mix of combustion and non-combustion emissions, with fuel combustion producing carbon dioxide (CO2), CO, NOx, …show more content…
PMs varying in size from between 2.5 μm and 10 μm in diameter are usually deposited in human nasopharynx, while finer PM of 2.5 μm and smaller in diameter are deposited in the bronchioles and in the alveoli of the human lungs (1). The fact that there is a positive correlation between poor air quality as a result of air pollution and ill health is well recognized and documented. Therefore any attempt to implement policy to reduce traffic is bound to yield a degree of improved air quality.
Epidemiological Methods, strengths and weaknesses
With increasing research focus on the effects of pollution on health. The primary methods employed in such studies are times-series studies and geographical studies (4). Time-series studies are ecologic in design – in that the unit of analysis is usually at the group level (such as a city or a region) (4). They are constructed to compare the same population against itself over short periods of time, by looking at short-term associations between the changes in pollutants and health outcomes such as mortality or morbidity counts (4). The available data on the outcomes (i.e. mortality / hospitalization records) are usually collected daily (no more than weeks at a time) and correlated with the data on the air pollution exposures …show more content…
Semi-ecological studies, also known as semi-individual studies are defined as studies where “individual-level data are available on outcome and confounders, with an ecologic exposure assessment” (13)Though expensive and time consuming, in such studies, the confounding factors relating to individual mortality / morbidity have been measured at an individual level and the air pollution exposure can be measured at the group level, thereby providing data on chronic exposure in a way that time-series studies and geographical studies are unable to
It is known that air pollution had adverse effects on the health of those exposed to it. There is a diverse mix of air pollutants and the most common pollutants in outdoor air include carbon monoxide (CO), nitrogen oxides (NOx), sulfur dioxide (SO2), ground level ozone and particulate matter (PM) (1). Outdoor air pollution is a mixture of gases and particulate matter (PM) of varying sizes and it is often difficult to isolate the source of the PM from all the possible sources of combustion (1). Traffic-related air pollution (TRAP) is a significant contributor to air pollution in urban areas and motor vehicles release a mix of combustion and non-combustion emissions, with fuel combustion producing carbon dioxide (CO2), CO, NOx, …show more content…
PMs varying in size from between 2.5 μm and 10 μm in diameter are usually deposited in human nasopharynx, while finer PM of 2.5 μm and smaller in diameter are deposited in the bronchioles and in the alveoli of the human lungs (1). The fact that there is a positive correlation between poor air quality as a result of air pollution and ill health is well recognized and documented. Therefore any attempt to implement policy to reduce traffic is bound to yield a degree of improved air quality.
Epidemiological Methods, strengths and weaknesses
With increasing research focus on the effects of pollution on health. The primary methods employed in such studies are times-series studies and geographical studies (4). Time-series studies are ecologic in design – in that the unit of analysis is usually at the group level (such as a city or a region) (4). They are constructed to compare the same population against itself over short periods of time, by looking at short-term associations between the changes in pollutants and health outcomes such as mortality or morbidity counts (4). The available data on the outcomes (i.e. mortality / hospitalization records) are usually collected daily (no more than weeks at a time) and correlated with the data on the air pollution exposures …show more content…
Semi-ecological studies, also known as semi-individual studies are defined as studies where “individual-level data are available on outcome and confounders, with an ecologic exposure assessment” (13)Though expensive and time consuming, in such studies, the confounding factors relating to individual mortality / morbidity have been measured at an individual level and the air pollution exposure can be measured at the group level, thereby providing data on chronic exposure in a way that time-series studies and geographical studies are unable to