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Tempo-Spatial Variations of Ambient Ozone-Mortality Associations in the USA: Results from the NMMAPS Data

View Article: PubMed Central - PubMed

ABSTRACT

Although the health effects of ambient ozone have been widely assessed, their tempo-spatial variations remain unclear. We selected 20 communities (ten each from southern and northern USA) based on the US National Morbidity, Mortality, and Air Pollution Study (NMMAPS) dataset. A generalized linear model (GLM) was used to estimate the season-specific association between each 10 ppb (lag0-2 day average) increment in daily 8 h maximum ozone concentration and mortality in every community. The results showed that in the southern communities, a 10 ppb increment in ozone was linked to an increment of mortality of −0.07%, −0.17%, 0.40% and 0.27% in spring, summer, autumn and winter, respectively. For the northern communities, the excess risks (ERs) were 0.74%, 1.21%, 0.52% and −0.65% in the spring, summer, autumn and winter seasons, respectively. City-specific ozone-related mortality effects were positively related with latitude, but negatively related with seasonal average temperature in the spring, summer and autumn seasons. However, a reverse relationship was found in the winter. We concluded that there were different seasonal patterns of ozone effects on mortality between southern and northern US communities. Latitude and seasonal average temperature were identified as modifiers of the ambient ozone-related mortality risks.

No MeSH data available.


Distribution of 20 study communities in the USA. Note: This figure depicts the distribution of selected communities in the USA through ArcGis (ArcMap 9.3, Environmental Systems Research Institute, Redlands, CA, USA). (A): The distribution of all included communities; (B): The location of three northern communities that are located closely each other.
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ijerph-13-00851-f001: Distribution of 20 study communities in the USA. Note: This figure depicts the distribution of selected communities in the USA through ArcGis (ArcMap 9.3, Environmental Systems Research Institute, Redlands, CA, USA). (A): The distribution of all included communities; (B): The location of three northern communities that are located closely each other.

Mentions: This study was based on the NMMAPS dataset for 1987–2000 obtained from the National Center for Health Statistics [28]. The dataset included information on air pollution, mortality and weather conditions for 108 large communities distributed across the USA. In order to achieve the present study aims, we randomly selected ten communities from a region that experienced a humid, subtropical climate (in this case, the southern region), and ten communities from a region with a temperate, continental climate (in this case, the northern region). High quality data were available for analysis in all the chosen communities. Along with direct differences in climate conditions, people in these two regions may have different activity models, which in turn might affect their exposure to ambient air pollutants [21]. The distribution of all selected 20 communities is shown in Figure 1 and their general information is shown in Table 1 and Figure S1. To test the seasonal variations of ozone effects on mortality in different regions, all data were divided into four seasons: spring (March−May), summer (June−August), autumn (September−November) and winter (December−February).


Tempo-Spatial Variations of Ambient Ozone-Mortality Associations in the USA: Results from the NMMAPS Data
Distribution of 20 study communities in the USA. Note: This figure depicts the distribution of selected communities in the USA through ArcGis (ArcMap 9.3, Environmental Systems Research Institute, Redlands, CA, USA). (A): The distribution of all included communities; (B): The location of three northern communities that are located closely each other.
© Copyright Policy
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC5036684&req=5

ijerph-13-00851-f001: Distribution of 20 study communities in the USA. Note: This figure depicts the distribution of selected communities in the USA through ArcGis (ArcMap 9.3, Environmental Systems Research Institute, Redlands, CA, USA). (A): The distribution of all included communities; (B): The location of three northern communities that are located closely each other.
Mentions: This study was based on the NMMAPS dataset for 1987–2000 obtained from the National Center for Health Statistics [28]. The dataset included information on air pollution, mortality and weather conditions for 108 large communities distributed across the USA. In order to achieve the present study aims, we randomly selected ten communities from a region that experienced a humid, subtropical climate (in this case, the southern region), and ten communities from a region with a temperate, continental climate (in this case, the northern region). High quality data were available for analysis in all the chosen communities. Along with direct differences in climate conditions, people in these two regions may have different activity models, which in turn might affect their exposure to ambient air pollutants [21]. The distribution of all selected 20 communities is shown in Figure 1 and their general information is shown in Table 1 and Figure S1. To test the seasonal variations of ozone effects on mortality in different regions, all data were divided into four seasons: spring (March−May), summer (June−August), autumn (September−November) and winter (December−February).

View Article: PubMed Central - PubMed

ABSTRACT

Although the health effects of ambient ozone have been widely assessed, their tempo-spatial variations remain unclear. We selected 20 communities (ten each from southern and northern USA) based on the US National Morbidity, Mortality, and Air Pollution Study (NMMAPS) dataset. A generalized linear model (GLM) was used to estimate the season-specific association between each 10 ppb (lag0-2 day average) increment in daily 8 h maximum ozone concentration and mortality in every community. The results showed that in the southern communities, a 10 ppb increment in ozone was linked to an increment of mortality of −0.07%, −0.17%, 0.40% and 0.27% in spring, summer, autumn and winter, respectively. For the northern communities, the excess risks (ERs) were 0.74%, 1.21%, 0.52% and −0.65% in the spring, summer, autumn and winter seasons, respectively. City-specific ozone-related mortality effects were positively related with latitude, but negatively related with seasonal average temperature in the spring, summer and autumn seasons. However, a reverse relationship was found in the winter. We concluded that there were different seasonal patterns of ozone effects on mortality between southern and northern US communities. Latitude and seasonal average temperature were identified as modifiers of the ambient ozone-related mortality risks.

No MeSH data available.