Research Question

What is the effect of air pollutants on hea diseases? 

Hypothesis

Null hypothesis: The hospital admission rates for those with and without exposure to air pollution is similar.
Alternate hypothesis: Those who are exposed to high level of air pollutants are more likely to get admitted to the hospitals with acute myocardial infarction diagnoses

Aims

The aim of this study is to gather ambient air quality from the city of Lautoka within a three months period and using appropriate statistical methods to compare the air quality data with recently published studies on ambient air pollution and the risk of acute myocardial infarction.

General Objective

To determine the level of air contaminants within the city of Lautoka and the potential effects it may have on the cardiovascular health of its urban population.

Specific Objectives

The specific objectives of this study are as described below:
  1. To assess the air quality in the city of Lautoka
  2. To conduct a meta-analysis of the association between air quality and hospital admissions due to acute myocardial infarction in Lautoka
  3. To predict hospital admissions due to acute myocardial infarction in Lautoka based on air quality data and estimates from the meta-analysis

Literature Review

Brief History of Air Pollution

Before the Industrial Revolution

Air pollution can be traced back to the tribes in early history whereby they lived nomadic lives in order to move away from the stench of animal, vegetable and human waste they generated. These early tribesmen also learned to use fire and this new knowledge was quite important in their daily lives and often its usage would fill the inside of their living quarters with the products of incomplete combustion. Examples of these can still be seen in some of the primitive parts of the world and later on, the invention of chimneys removed the combustion materials and cooking odours from the living spaces.
In the bronze and iron ages,  the principal industries associated with the production of air pollution such as dust and fumes were from metallurgy, ceramics and preservation of animal products. These industries were responsible for the baking of clay for pottery and bricks before 4000BC and the production and use of iron before 1000BC. During this period, people relied on charcoal rather than coal or coke as a source of fuel\cite{vallero2008}. However, the burning wood in fireplaces inside homes created emissions that were smoky and in AD 61 Roman philosopher Seneca mentioned that, " As soon as I had gotten out of the heavy air of Rome and from the stink of the smoky chimneys thereof, which, being stirred, poured forth whatever pestilential vapors and soot they had enclosed in them, I felt an altercation of my disposition\cite{VALLERO_2008}.
Later on in 1157, Eleanor of Aquitaine, the wife of King Henry II of England moved away from Tutbury Castle because she deemed  burning wood as unendurable. A hundred and sixty years later the burning of coal was prohibited in London but in 1306 Edward I issued a Royal proclamation authorizing the use of sea coal in furnaces. By 1661, air pollution in London was a huge problem that prompted John Evelyn to advise the parliament and King Charles II on the quality of air in London with possible remedies to control air pollution and these remedies are still relevant in the 21st century \cite{P_J_B__1956}.

       The Industrial Revolution

The Western civilization embraced the industrial revolution because it brought prosperity, social changes and it also altered the directions. However, it's downside was the industrial reliance on coal as an energy source and the severe air pollution that accompanied this\cite{rl1999}. The harnessing of steam to provide power to move machinery and pump water began in the early years of the 18th century and culminated in 1784 in Watt's reciprocating engine which was later displaced by the steam turbine in the twentieth century \cite{ca1994}. As a consequence of this revolution, there was a lot of pollution from the smoke and ash from the burning of coal in the boiler furnaces of stationary power plants, locomotives' home heating fireplaces and furnaces.   In 1819, Great Britain took the initial steps to address the problem of air pollution and by 1856 laws specifically for London were introduced to reduce the impending problem and deemed the emission of smoke as a public health nuisance \cite{Beaver_1955}. In 1880, The United States of America developed municipal ordinances and regulations targeting the emission of black some and ash from industrial, marine and locomotive sources. Despite the introduction of new laws to curb the emission of smoke and ash in major industrialized countries, air pollution was at its worst as the 19th century drew to a close.

The 20th Century

In the early 1900s, there was still a reliance on the use of coal but technological advances such as the replacement of the steam engine with the electric motor was a major breakthrough. Towards the end of the first quarter of this century, the use of coal had been taken over by pulverized coal, oil and gas but each one of them produced its own characteristic emissions to the atmosphere. During this period there was a decrease in ash emissions as oil had replaced the use of coal, and as a consequent, there was a significant increase in the production of automobiles. In addition, the perfection of the motor driven fan together with the invention of the electrostatic precipitator allowed the establishment of large scale gas treating systems and the control of particulates more feasible \cite{vallero2008}. The period 1925 and 1950 saw the emergence of the present day pollution problems such as the  Meuse Valley smog in 1930 which killed sixty people as a result of a combination of air pollution and climatic conditions \cite{j1931}. In 1948, an air inversion episode similar to that shown in Fig. 2 ( arrows show airflow in normal conditions on the left and during temperatures inversion on the right. In normal conditions, warm air rises and normal convective patterns persist. During a temperature inversion, the warms air acts as a cap, effectively shutting down convection and trapping smog over a city) and known as the Donora Smog occurred in Donora, Pennsylvenia which resulted in a wall of smog that killed almost forty people and left nearly half of the town's 14,000 residents experiencing severe respiratory or cardiovascular problems  \cite{usepa2017}. An air inversion is an event in which air stops circulating and is trapped close to the ground. The combination of trapped toxic gasses and early morning mists yields disastrous effects. Another incident was in Poza Rico in Mexico whereby twenty two people were killed and three hundred people hospitalized as a result of an accident release of hydrogen sulfide (H2S) from a natural gas plant in the city \cite{yu2001}. The city of Los Angeles also experienced the effects of smog in the 1940s as a result of the influx of cars and industries, combined with a geography that traps fumes.