Article Citation in APA format
Beelen, R. et al. (2008). Long-term effects of traffic-related air pollution on mortality in a Dutch cohort (NLCS-AIR Study). Environmental Health Perspectives, 116 (2), 196-202.
Research Question
Is there a relationship between the death rate and exposure to air pollution from traffic?
Health Outcome of Interest
There is a relationship between the death rate and exposure to air pollution from traffic.
Exposure(s) of Interest
Air pollution, which is caused by traffic, has different mortality effects to the people living between-city and those living within the city.
Type of Study
This study is prospective. The study was conducted together with another study about diet and cancer. The two studies were conducted from 1987 to 1996 and the same subjects were used to collect data.
Description/Ascertainment of Cohort
The participants were drawn from a previous study conducted by the Netherlands Cohort Study on Diet and Cancer. The research was started in 1986, and the population of the study had 120,852 subjects. The participants were aged 55 to 69, and they lived in 204 municipalities.
Data Collection of Baseline
Questionnaires were used to collect data from the subjects. The questionnaire had 11 pages.
Type, Frequency and Duration of Follow-Up
Record linkage follow-up was conducted. The frequency and duration of the follow-up have not been mentioned
Type of Data Analysis (include a measure of association used)
Cox Proportional hazards framework was applied to analyze the collected data. Cox-Poisson effects survival software was used to include spatial clustering process to include the scales of municipal and neighborhood during the cohort analysis. In addition, the analysis involved one-level and two-level analysis.
Results/Main Findings of Study
There is a relationship between exposure to air pollution from traffic and the rate of mortality. The higher the exposure to traffic pollution the higher the mortality rate. The relationship between exposure to NO2, BS and natural gases and the death rate is significant. The gases were found to affect the respiratory system of the patients, and this was a major cause of death.
Assessment of Bias (selection and information)
The information collected was biased because the data was collected from a few people. The data were collected from people aged 55-69 years. This shows that was age bias because the impact of traffic pollution can have different impacts to different age groups. People aged 55-69 years are susceptible to diseases and they are likely to have higher mortality rates. Therefore, the research should have been conducted in all age groups to provide a fair representation of the participants.
Assessment of Confounders
Confounding is the process of providing explanations that are alternative in the association between the dependent and independent variables. This happens when the observation made in research is distorted by other risk factors (Doll & Hill, 1999). The mortality could have resulted from other variables such as cancer or dietary diseases.
Comments
The research was conducted to establish the relationship between exposure to air pollution that is caused by traffic and mortality rates. Questionnaires were used to collect the data. The findings show that the hypothesis was accepted because the findings show that there is a link between exposure to air pollution that is caused by traffic and the mortality rates. The research is important because it helps reduce the rate of mortality which is caused by traffic pollution.
References
Beelen, R. et al. (2008). Long-term effects of traffic-related air pollution on mortality in a Dutch cohort (NLCS-AIR Study). Environmental Health Perspectives, 116 (2), 196-202.
Doll, R. & Hill, A. B. (1999). Smoking and carcinoma of the lung. Bulletin of the World Health Organization, 77 (1), 84–93.