In a series of major epidemiological studies, it has been established that air pollution has adverse effects on cardiovascular health\cite{Dockery_1993}. Brief exposures to air pollution have been associated with increased cardiovascular-related morbidity and mortality from angina, myocardial infarction, arrhythmia and heart failure and this pathologic link have particular implications for low-income and middle-income countries\cite{Samet_2000}. These countries are rapidly developing, hence, air pollution concentrations are continuing to rise. Long-term exposure to air pollution increases the risk of an individual to coronary heart disease and the main arbiter of these health effects seems to be the combustion-derived particulate matter. 
In a study by Barnett et al. 2006 on the effects of air pollution on hospitalizations for cardiovascular disease in elderly people in Australia and New Zealand cities, they found that particulate matter (PM10 and PM2.5), NO2, SO2 and CO were significantly associated with higher admissions amongst the elderly (\(\ge\)65yrs) than the younger age group (15-64). O3 was the only pollutant that showed no association.  Findings from this study suggests that for a 0.9ppm increase in CO, elderly admissions increased for total cardiovascular disease (2.2%), all cardiac disease (2.8%), cardiac failure (6%), ischemic heart disease (2.3%) and myocardial infarction (2.9%). Their advanced age, frailty and with probably preexisitng heart conditions could be a reason for the vulnerability of the elderly population. Interestingly, these associations were found at concentrations that were below normal air quality health guidelines and the author's suggest that these guidelines have to be revised and lowered if possible. Lowering these guidelines will lead to improvements in cardiovascular health\cite{Barnett_2006}.
Another study by \cite{Liu_2015} on the association between air pollutants and cardiovascular disease mortality in China demonstrated that increases in NO2 and SO2 was significantly associated with daily cardiovascular mortality. No significant associations were found for PM10.  Moreover, the study suggests that for the elderly (65 years and older), significant associations were found between PM10 and SOwith ischemic heart disease mortality.
                                                                                                                  

Ambient Air Pollution and Acute Myocardial Infarction

Acute myocardial infarction is the medical name for a heart attack and is a life-threatening condition that occurs when blood flow to the heart muscle is abruptly cut off, causing tissue damage. This is usually the result of a blockage in one or more of the coronary arteries. A blockage can develop due to a buildup of plaque, a substance mostly made of fat, cholesterol, and cellular waste products. 
Epidemiological studies such as that by \cite{Peters_2001}have demonstrated a significant increase in the incidence of adverse myocardial infarction in the immediate periods (hours to days) after exposure to high levels of atmospheric PM2.5. In addition, findings from the study suggests that increasing concentrations of fine particulates in the air may elevate the risk of myocardial infarction after a few hours to a day after exposure. Moreover, even low and moderate PM2.5   concentrations were associated with an increased risk of myocardial infarction.
Furthermore, in a meta-analysis study by \cite{Mustafi__2012}, the authors systematically reviewed associations between the air pollutants ozone, carbon monoxide, nitrogen dioxide, sulfur dioxide, PM10 and PM2.5 levels and the risk of myocardial infarction. The findings from this meta-analysis demonstrated that all the air pollutants i.e. CO, NO2, SO2, PM10 and PM2.5 , with the exception of ozone were significantly associated with a near-term increase in myocardial risk.

Population and Methods

Study Design

A combination of meta analysis, collection of field data on air quality by measuring criteria pollutants excluding lead and developing a dose-response model of the association between criteria pollutants and the risk of acute myocardial infarction. 

Data collection

Air Quality Monitoring

Collection of field data on air quality will be for a period of 3 months and measurements will be taken for the common criteria pollutants (SOx, NOx, PM10, PM2.5, O3, CO). The measurements will be conducted in 3 selected sites in Lautoka (industrial, residential, and commercial (city centre)); measurements will be taken at human breathing height of 1.5m above the ground. The criteria pollutants to be monitored in this study according to \cite{Chen_2008}, are  often used as indicator pollutants for fuel combustion and traffic-related air pollution and the study by \cite{Isley_2017} confirms the increasing dependent on fossil fuels, in particular diesel for Pacific Island countries. To  provide sufficient data to determine trends in air quality over the 3 months period as well as the background levels of contaminants , the WHO recommended threshhold measurements will be used as shown in Table 3 with the description of the time-averages adopted from the National Environment Standards (NES) provided in Appendix A. The ozone guideline value and measurement time has been adapted from the Ambient Air Quality Guidelines (AAQG) of New Zealand. The equipment of choice to conduct this monitoring  measures the air contaminants in part per billion (ppb) and the quick reference conversion table provided in the  Guide for Air Quality Monitoring and Data Management 2009  and appended in Appendix B will be utilised to convert the measurements from ppb to \(\mu\)g/m3