The world’s population increased from 1 billion in the 1800 to over 7.7 billion today; a dramatic increase since it had changed very little in the previous periods, constantly being checked by prolonged periods of starvation and pestilences, inadvertently; the high death rates leveled out the birth rates. In the 100 years between 1900 and 2000, the increase in world population was three times greater than the entire previous history of humanity and this jump is attributed to many factors that shifted the demographic paradigm.
Health improvements were one of the fundamental pillars that spurred on the dramatic rise in population, seeing that great numbers of populations had been wiped out in the previous periods without decisive or effective efforts to end the pestilences; there were enormous fatalities. The improvements in health have since reduced death rates.
In Eurasia and North Africa, the Black Death (Bubonic plague pandemic) in the mid fourteenth century had deaths estimated between 75-200 million deaths. The series of Smallpox epidemics in Chile and Mexico in the 16th century caused fatalities in millions. The Black Death and Smallpox are just some of the many pestilences that have troubled the world.
The discovery of Smallpox vaccine in 1796 as the first vaccine developed and Penicillin in 1928 as the first true antibiotic were shining lights in world’s history as the first success stories of a health system that would further improve for the betterment of the world. Since then; over 25 vaccines have been discovered, with some requiring multiple doses at specific ages, and more than 100 antibiotic molecules have been discovered to fight against bacterial infections.
However, many other factors have come up over time in the studies of population growth and its impact. The concerns have been raised during discussions of climate change; often posited as a result of the impact of increasing population on the finite world resources. Globally, the number of women in reproductive age using some form contraceptives increased from 42% in 1990 to 49% in 2019 (Source: United Nations)
The UN also reports that long term population trends are largely driven by fertility; and over the past two decades, rates of birth have fallen steadily and fertility levels are projected to continue declining globally. According to UN reports, the fertility rate in sub-Saharan Africa is projected to fall from 4.6 live births per woman today to 3.1 in 2050 and a further 2.1 in 2100.
Since masses of populations are concentrated in specific regions. The urbanization that gave birth to cities came with its challenges and concerns of poor health in densely populated settlements; cholera outbreaks have been commonplace in places of poor hygiene often found in crowded settlements, where modern slums are epicenters.
The relationship between health and population is perpetual, oftentimes; one will have marked effects on the other at particular periods and hence discussions of these topics are seldom held in isolation.