Metro prevents US$18 billion in annual spending on pollution-related deaths in São Paulo

Study points to a 75% increase in the concentration of pollution and a 14% increase in deaths due to cardiorespiratory problems if Brazil’s largest city had no metro for a year

By Karina Toledo

Agência FAPESP – If the São Paulo Metro were to stop working for an entire year, the concentration of pollutants in the city would increase by 75% and the deaths due to cardiorespiratory problems would increase by 9-14%. This would represent a cost of US$18 billion to the municipality.

This estimate was made by researchers from the Universidade Federal de São Paulo (Unifesp) in an article published this month in the Journal of Environmental Management.

To perform the calculation, the scientists compared air pollution levels in São Paulo on normal days with those on days when the Metro was on strike. Then they determined that the numbers of deaths were higher on the days when the Metro was stopped and calculated the loss of productivity that this represented in the statistical context of the population.

“We chose two strikes that lasted for 24 hours each, one in 2003 and the other in 2006. We then evaluated the concentration of pollution on the days before, during and after the strike,” said Simone Georges El Khouri Miraglia, coordinator of the study and member of the National Institute for Integrated Analysis of Environmental Risk (Inaira), one of the National Science and Technology Institutes (INCTs) financed by FAPESP and the CNPq in the State of São Paulo.

The two strike situations were analyzed separately and compared with a “control day.” “We chose a day in the same month, in the same year, on the same day of the week and with similar weather conditions for pollution dispersion,” explained Miraglia.

In 2003, the concentration of pollution on the control day was 41 micrograms per cubic meter (µ/m³). On the day of the strike, the number jumped to 101.49 µ/m³. The equivalent of 8 additional deaths associated with pollution were identified during the strike, representing an increase of 14% and a cost of US$50 million.

“To evaluate the economic impact of these additional deaths, we worked with a revision of studies done by the American Environmental Protection Agency that established the Value of Statistical Life. It is an average value that takes into account, among other factors, the income that this person would have if he or she were alive,” said Miraglia.

In 2006, the impact was found to be lower. Pollution levels jumped from 43.99 µ/m³ on the control day to 78.02 µ/m³ during the strike. There were six additional deaths, representing an increase of nearly 9% and US$36 million in lost productivity.

“Our hypothesis for explaining the lower impact in 2006 was the renovation of the fleet of vehicles in the city. New cars are less polluting and, because of this, the pollution level at the base of the calculation fell,” said Miraglia.

Based on these results, the researchers estimated health costs in the event that the Metro were to stop working for one year. “We took the data and multiplied them by 365 days. The result was US$18 billion. I don’t think we are far from the real number. We were actually conservative,” stated the researcher.

Savings and more health

According to Inaira data, 90% of the air pollution in São Paulo is generated by cars, motorcycles and trucks. Individual transport is responsible for 45% of all travel within the city, and public transport is responsible for 55%.

“Our motorization rate is very high, and 1,200 new cars are licensed every day in the city. It is an unsustainable scenario. Aside from immobility, it is creating many other social costs,” Miraglia pointed out.

Of the various means of mass transit, buses are responsible for carrying 71% of all passengers, the metro carries 24% and trains carry 5%. According to the researchers, three lanes of cars on an avenue such as the Marginal on the Rio Tietê have the capacity to transport 5,450 passengers in an hour, whereas one bus lane can carry up to 6,700 passengers and a Metro track can carry 60,000.

“It’s urgent that we increase the subway system coverage,” Miraglia said. “The excuse for the lag has been the high costs of construction and operation. But when you insert the socio-environmental variable to the cost-benefit equation, the advantages for health are much greater than the costs.”

For Universidade de São Paulo School of Medicine (FM-USP) professor Paulo Saldiva, all measures for reducing pollution bring profit. “Investments in transportation result in less spending in the health sector,” he said.

The study coordinated by Miraglia led to a master’s thesis defended by Cacilda Bastos Pereira da Silva at Senac/São Paulo.

The article Evaluation of the air quality benefits of the subway system in São Paulo, Brazil, by Cacilda Bastos Pereira da Silva and others, can be read at www.sciencedirect.com/science/article/pii/S0301479712000606.