San José, Costa Rica, since 1956

New Air Quality Study Shows Mixed Results

Scientists released good news and bad news about San José’s air quality this week. The good news: for the first time, they have recorded a decrease in particulate matter such as dust, soot and ash, and less sulfur in this debris. The bad news: levels of nitrogen dioxide have continued to rise, announced Jorge Herrera, director of the Universidad Nacional (UNA) Environmental Analysis Laboratory during a press conference Tuesday.

Herrera called the reduction in particulate matter, which hangs in the air after being spewed by vehicles and factories and exacerbates respiratory problems, an “encouraging” find. It can likely be attributed to the National Oil Refinery (RECOPE) requiring lower sulfur levels in the country’s fuels. As a result, less sulfur is creeping into exhaust, he explained, addressing journalists as well as San José Mayor Johnny Araya, Public Health Minister María Luisa Avila and Environment and Energy Minister Roberto Dobles.

However, the other finding, an increase in nitrogen dioxide, is less than encouraging, Herrera said. For the past three years, his study has measured nitrogen dioxide levels at 14 places around San José. The results presented this week, which measured the air from 2005-2006, show that the air at 65% of these places had an increase in this harmful gas compared to the previous year. Additionally, five points showed levels higher than the 40 micrograms per cubic meter recommended by the World Health Organization (WHO).

Not coincidentally, these places are on streets where swarms of exhaust-coughing buses converge: near the San Juan de Dios Hospital on Paseo Colón, the Metropolitan Cathedral on Ave. 2, the La Castellana gas station on Ave. 10, the National Water and Sewer Institute (AyA) building on Paseo de los Estudiantes and the Numar building in Barrio Cuba. The first four points were identified in previous studies as exceeding WHO limits (TT, Nov. 5, 2004; TT, Jan. 27, 2006); the Barrio Cuba point is new this year.

The culprit? According to Herrera, an approximately 9% increase in the number of cars on the city’s streets every year.

“It’s cultural; people are preferring to drive their own cars rather than use public transportation,” he said.

According to statistics provided by UNA, in 1984, there were 205,444 vehicles in Costa Rica, or one for every 12 people. By 2002, that figure had more than tripled to 798,710 cars, or one for every five people. Last year, one in every four Ticos had a car, according to Minister Dobles.

Additionally, most people are driving older vehicles – on average, cars here date back to 1992, above WHO’s recommended 10-year average age for cars.

Cleaning Up the Air

To improve air quality, it’s up to citizens to use public transportation more often, and it’s up to government officials to overhaul the bus system, Herrera said.

Unlike sulfur and particulate matter, nitrogen-dioxide levels are not dependent on the quality of fuels, but rather on the quantity of vehicles.

Multiple bus companies are traversing the same crowded routes, but they’re only 34% full, Herrera said. Additionally, getting from one suburb to another by bus requires passing through San José, creating another pollution bottleneck.

The researcher called on the ministries of Environment and Energy (MINAE) and Public Works and Transport (MOPT) and the Municipality of San José to collaborate on actions to solve these problems.

“This has to be an inter-institutional job – redesigning our public transportation system to make it more efficient and use cleaner technologies,” he said.

The San JoséMunicipality supported the UNA study as part of a joint Green Agenda program to make environmental data available for decision-making. Next year, researchers will use additional air meters to measure both nitrogen dioxide and particulate matter; studies of rivers and solid-waste management are also in the works.

Dobles remarked after Herrera’s presentation that MINAE will be taking his findings into account as it plans to combat global warming, a problem he recently discussed with global leaders at climate change conferences in Paris and Nairobi.

Meanwhile, Araya pointed to his municipality’s urban tree-planting program and construction of a pedestrian walkway along Ave. 4 as projects will make the capital more pedestrian friendly, ultimately improving air quality.

Reorganizing bus routes, obtaining more modern vehicles and implementing “clean technologies” like an electric train are other projects Araya said he has long championed. However, it’s up to MOPT to make them happen, he said.


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