Global Explosion of Slums: The Next Biggest Planetary Health Challenge

Caracas Slum in Venezuela (source: Taxi to Caracas)

When someone talks about the biggest future threat to our planet, what comes to your mind first? Is it ISIS? Nuclear war? A new pandemic? Immigrants taking your jobs? Maybe even the craziest possibility of an Independence day-style alien invasion? No one in their wildest imagination thinks of slums as a major impending threat to our planet, but it actually might shape up to be so in the near future.

By 2050, the slum population is expected to grow to more than three billion — that’s more than 30% of the projected population of 9.7 billion in 2050.

According to the United Nations, more than one billion people now live in the slums of the world’s cities, and by 2050 the slum population is expected to grow to more than three billion — that’s more than 30% of the projected population of 9.7 billion in 2050.

The most obvious factor driving this explosion of growth is rapidly rising urban populations. As more and more people migrate to cities for jobs and better quality of life, proper and systematic urbanization is practically impossible to achieve, leaving many people to take up residence in mega slums around the world.

Another driver of slum population growth is the current unprecedented global refugee and displacement crisis. Globally, there are 40 million internally displaced persons and over 21 million refugees living in and outside of camps. The ongoing protracted refugee situations around the world have resulted in the creation of slum-like situations in the camps themselves, and those who flee to urban areas are known to once again end up in urban slums.

So how can we address this exploding population? First, we have to understand the risks and threats that exist in slums. Based on my experience living in a slum for the first several years of my life and near one for the rest of it, I would divide these into two major categories: direct, visible risks and threats that we are likely all cognizant of; and insidious, underlying risks and threats that we usually don’t see until they surface, when it’s too late to even attempt to alleviate them.

Solid waste floating in the canal in Klong Toey Slum in Thailand (source: Chiangrai Times)

Direct environmental and health risks arise from the crammed unhygienic living conditions in slums and the pollution of nearby rivers, ground water, land, and air. As a part of an urban development research group at the University of Tokyo, I traveled to Klong Toey in Thailand and Kampung Cikini in Indonesia, two of the largest slums of Asia. These communities were very similar to the slum I grew up in — built near rivers, which not only provide water for daily consumption, but also act as outlet for waste from hundreds of slum households; full of crammed spaces and houses which rarely let fresh air in; and overflowing with unsightly solid waste that turns the streets into hideous mosaics.

These conditions make slums highly vulnerable to a plethora of diseases and infections, including cholera, typhoid, dengue, malaria, and more. In fact, The Lancet reported that one of the main causes for the spread of the Ebola epidemic in West African countries like Liberia was the conditions in urban slums. We can only imagine what the situation might have been if the slum population in the Ebola hotspots was triple what it is now.

…one of the main causes for the spread of the Ebola epidemic in West African countries like Liberia was the conditions in urban slums.

Structural inequities in slums partially comprise the second category of less-obvious risks. Health and gender inequities, deep poverty, violence and abuse, homelessness, and other complex social problems render slum dwellers vulnerable to grave social injustices and human rights violations. The stark disparity and divide between slums and urban centres, and even within slums themselves, can create a sense of isolation and alienation among slum dwellers, contributing to ethnic rivalry, cultural grievances, gang wars, and religious-ideological extremism.

The world today is already marred by vast economic, social, and gender inequalities — where will we be in three decades or so when over 30% of the global population will be living in urban slums?

Slums are also considered to pose substantial threats to national security. The negative social realities of slums have often allowed for relatively easy recruitment of foot soldiers and collaborators into criminal and terror networks. Further, slums are known to be a good hideaway and a safe haven for criminals, terrorists, and insurgents.

Kampung Cikini Slum in Indonesia

The world today is already marred by vast economic, social, and gender inequalities — where will we be in three decades or so when over 30% of the global population will be living in urban slums? We are fast heading towards one of the biggest calamities our planet will ever witness, and yet we are blissfully unaware, and most often ignorant of it.

From potential health risks to substantial national security threats, the future explosion of mega slums is definitely a disaster in the making unless we act now. On the occasion of Earth Day, we must commit to working on mitigating these risks and threats before they escalate and spin out of our control.


Sarju Rai is a 2016–2017 Global Health Corps fellow.