Physiological Determinants of Global Health

Introduction

“The potter is covered with earth, although his lifetime is still among the living. He burrows in the field more than swine to bake his cooking vessels. His clothes being stiff with mud, his head cloth consists only of rags, so that the air which comes forth from his burning furnace enters his nose.” The Satire of Trades, from 12th century B.C. depicts an early account of the environmental conditions that workers face each day in Middle Kingdom Egypt. The account continues to describe a furnace-tender, “His eyes are inflamed because of the heaviness of smoke. He cannot get rid of his dirt, although he spends the day at the reed pond.”¹ In the Middle Ages, stories of the plight of workers described how blacksmiths were consumed in rooms full of fumes from furnaces and smoke from metal smithing. During the Industrial Revolution, not only did factories and manufacturing rise, but so did respiratory diseases. Diseases caused by cotton dust, mining smoke, fumes from metal works, and crop dust became more prevalent. By the early mid, 19^th century, respiratory diseases like pneumoconiosis, chronic bronchitis, byssinosis, and lung cancer were affecting the masses. Elizabeth Gaskell describes the plight of British cotton workers in the novel North and South. “Fluff got into my lungs and poisoned me…little bits fill the air till it looks all fine white dust…it winds round the lungs, and tightens them up. There’s many…that falls into a waste, coughing and spitting blood.” ² Air pollution from industry and from the urbanization of cities forced people to breath in air polluted by harmful particles, dust, and chemicals that caused disease. Today, similar problems continue to challenge all nations.

In a CNN report on February 2014, New Delhi, India was crowned the dirtiest city in the world. The World Health Organization reported that in 2014, India’s annual average of small particulate matter (PM_2.5) was 153 micrograms per cubic meter. ³ PM_2.5 means particulate matter that is very small, only 2.5 micrometers in size. An AQI (Air quality index) of over 100 or PM_2.5 levels above 35 micrograms per cubic meter signifies that the public should be concerned for their health and safety.⁴ China's Beijing was a close second and held the distinction in recent years. In comparison, United States’ PM_2.5 annual average levels only ranged between 7- 18 micrograms per cubic meter during the period of 2000 to 2013.⁵ Though some countries are making a concerted effort to improve air quality, air pollution is still a global problem. According to WHO, 7 million premature deaths in 2012 were linked to air pollution.⁶

Many nations, including the United States, have strict air quality controls, but developing countries struggle to enforce changes that could improve air quality. Burns et al. state particulate matter pollution disproportionately affects urban and rural populations in developing countries. One reason for this is the cost of meeting safe air quality levels. The US alone in 2011 spent 65 billion dollars to meet Clean Air Act regulations.⁷ The price tag is a steep one to meet for many countries who simply cannot afford to spend billions of dollars regulating air quality. A study by Kanervisto et al. links low socioeconomic status (SES) and chronic obstructive airway diseases. They conclude that the socioeconomically disadvantaged had higher incidences of reporting COPD and asthma. Factors including smoking, physical inactivity, obesity, poor nutrition, lack or little education all contributed to increase reporting of two mentioned respiratory ailments. ⁸