‘Designed for death’ the mumbai housing blocks breeding tb cities the guardian

The report, which studied three housing projects through surveys and modelling experiments, found that 8-10% of the residents in the denser, less light-filled and more poorly ventilated complexes had tuberculosis – compared with 1% of residents in a better ventilated project. Even within a building, the risk of TB declined on higher, airier floors.

The government-funded report blamed the relaxation of building norms for slum-rehousing projects. The result: too many people in buildings stacked too close together, with poorly designed windows that residents keep shut, and lower floors with little natural light or air circulation.

The link to TB would not have surprised civic authorities a century ago.

Disease outbreaks in 19th-century cities led to the birth of modern urban planning as reformers, still new to germ theory, blamed crowding, poor ventilation and sanitation. Industrial Bombay, with its booming textile mills and migrant workers, was no different.

The outbreak of bubonic plague in 1896 led to the creation of the Bombay Improvement Trust (BIT), which over the next few decades opened up crowded neighbourhoods. It constructed east-west roads that brought in the sea breeze, and built new tenement housing, known as chawls, with cross-ventilation. It also sought to expand the city with new suburban layouts – modelled on London’s garden suburbs of that era. And it helped introduce the “63.5 degree light angle rule”, which determined building setbacks to optimise light and air right up to the 1950s.

Even then, economic interests were kept firmly in mind. “In fixing our standards of open space, which are the check [on the spread of disease], we must steer between the Scylla of encouraging bad building and the Charybdis of discouraging building altogether,” said BIT chairman James Peter Orr. Orr later became housing director of the London county council, whose projects were influenced by Bombay chawls.

Similar housing laws were introduced in most cities of that era, including New York, where the State Tenement House Act of 1901, enforced by the health department, mandated that every room have an external window. The rise of skyscrapers focused attention on access to sunlight, leading to zoning and setback laws that have caused the distinctive tapering tops of high-rises such as the Empire State Building.

Sunlight isn’t as much of a design issue for tropical cities such as Mumbai, says Prasad Shetty, faculty member at the city’s School of Environment and Architecture. But ventilation is. The chawls of old Bombay were well spaced because planners understood that the higher the density and the smaller the house, the more space you need around it. Not just for light and air, either: “When you have small, crowded homes, you require outdoor spaces to live life – especially for children and old people,” Shetty says, adding that modern planners have forgotten the lessons of older housing projects.

Part of the reason for the amnesia is that the historical link between health and urban planning weakened as incomes grew, sewers became the norm and – most importantly – medicine became better at treating disease. Yet in poor urban neighbourhoods, the environment remains a health risk – especially for airborne TB. According to the World Health Organisation, overcrowding, poor ventilation, malnutrition, stress and social deprivation are all risk factors for the illness.

With multi-drug resistant tuberculosis on the rise, environmental interventions are even more critical to prevent infection, said Singh, who has run a clinic in Govandi since 2010. India has a quarter of the world’s TB cases, and Mumbai is a hotspot.