Jocalyn Clark @jocalynclark discusses the urbanisation of the world’s population and its impact on global health.
Undeniably the world is urbanising. By 2050, according to the UN, the world’s urban population will almost double from its 2007 size of 3.3 billion to 6.3 billion people. The developing world will have more urban than rural dwellers by 2030. In terms of health, urbanisation gives rise to new threats and needs when delivering services.
Migration to cities usually means job prospects, educational opportunities, access to health care, and financial security for families. It can bring relief from conflict or land degradation. But it also brings problems associated with inadequate housing, overcrowding, air pollution, and road traffic. Both infectious (pneumonia, tuberculosis) and non-communicable (cardiovascular, diabetes) diseases increase with urbanisation.
I thought I knew big cities – the opportunities and the inconveniences – having lived in Toronto and London and travelled to many more across the developed and developing worlds. Then I moved to Dhaka, one of the world’s fastest growing cities (it grew an astonishing 45% between 2000-2010). Already 14 million people and densely crowded, by 2025 the UN predicts Dhaka will be home to more than 20 million people — larger than Mexico City, Beijing or Shanghai. Without the infrastructure, planning, or governance of those wealthier cities, Dhaka is like a poor cousin of mass urbanisation. Or, as a commentator recently said, it’s the ‘mega city of the poor.’
Mega cities take big city problems and amplify them. There were 10 mega cities (cities with 10 million inhabitants or more) in 1990; there are now 33 – 26 of which are in the developing world. The typical urban issues of climate vulnerability, safety and homelessness can literally engulf mega cities. In turn, the urban poor are disproportionately affected by urbanisation challenges.
This is particularly true of slums, the great, sad reservoirs of urbanisation. In Nairobi, for example, where 60% of the city’s population lives in slums, child mortality in the slums is 2.5 times greater than in other areas of the city, according to WHO. In Kolkata, slum dwellers were found to have higher risk of respiratory infections, meningitis, and asthma than other urban residents.
For climate threats the risk is double-edged. Environmental degradation due to climate change may force a rural Bangladeshi farmer to seek work in the city, but inadequate housing, infrastructure and emergency response means his slum dwelling makes him even more vulnerable in the event of extreme weather like floods or landslides.
Though proximity of health facilities is often touted as a positive aspect of urbanisation, it’s questionable how healthcare alone can address some of these broader challenges. Even where there is evidence of contact with health services – 70% of women in the urban slums of Dhaka use contraceptives, for example – this doesn’t mean even basic public health infrastructure or services are provided. Close proximity to a public or private health facility (or an NGO health worker who visits regularly) fails to overcome the health risks associated with the appalling living conditions of most slums: water sources and latrines are often shared, unhygienic and unserviced. Electricity is patchy at best. The Bangladesh government apparently denies the existence of slums and the fact that 40% of Dhaka residents are now slum dwellers – unsurprisingly, it does not provide public works to these slums.
I recently visited an urban slum, Kamalapur, that serves as a field site for icddr,b. Now comprising an estimated 350,000 inhabitants within a 4 square kilometre area in southeast Dhaka, Kamalapur has no sanitation disposal and a contaminated water supply. The median household income is less than US$60 per month, and people who live there usually have no more than 3 or 4 years of education. As I toured various households with a health worker collecting demographic surveillance data and conducting health screening, the cramped, dusty, dire conditions expected of a poor urban slum were evident. But so was the pride taken in keeping a clean and tidy living space, with family pictures hung on the wall and blankets and clothing folded neatly on shelves. The main street of the slum was bustling with fish and meat sellers, convenience stores, a recycling ‘depot’ and even a hotel. The kids were typically gregarious at spying a visitor and were so playful and inquisitive with me that I forgot to ask why they weren’t in school.
Clearly urbanisation is a major force in the world’s development, and cities including their slum areas are a hotbed of challenges. Advocates stress that building sustainable cities will be a major factor in the success of the post-2015 global health agenda. But in the current goals proposed to replace the MDGs, the vague language feels very far off from the realities of urban slums: “enhance inclusive and sustainable urbanization and capacities for participatory, integrated and sustainable human settlement planning and management in all countries.” Rising to the challenges of urbanisation needs a dedicated, nuanced focus, not forgetting the most vulnerable.