“Black Carbon” Chokes Chilean Towns

Temuco smogOn winter nights, Carmen Ahumada is unable to see across the street to her neighbor's house. Visibility in Temuco, Chile, can be as low as five meters at times, she said.

Temuco, with a population of 300,000, has the fourth most polluted air in the country, according to local media. The burning of firewood for heating, cooking, and other uses is the main source of soot particulates, known as "black carbon," that enter the air at levels 150 percent higher than the national standard and more than four times the World Health Organization's recommended limit.

In 2008, Temuco violated Chilean air pollution laws on 34 days, three times the number of days as in 2004.

Cold weather conditions, especially at night, trap urban air pollution near the ground, cloaking Chile's urban areas in thick smog. The problem worsens during the winter, when lower temperatures and poor home insulation ratchet up the amount of firewood burned.

"There are a lot of people here who suffer because of the pollution. The government promises and promises to help," Ahumada said. "The day arrives, and nothing happens."

On many counts, Chile has taken the lead in Latin America in tackling urban air pollution. But little has been done to help smaller towns address particulate pollution from firewood burning, which supplies 20 percent of the country's energy, according to local residents and officials.

Firewood use in the world's poorest regions has been recognized as a contributor to local air pollution, public health concerns, and more recently global climate change. Yet even in Chile, the most prosperous nation in South America, locals are struggling to overcome the effects of black carbon.

About a third of the world still burns wood and other biomass for cooking, heating, and lighting, accounting for 13 percent of global energy consumption. But burning does not completely break down the wood, resulting in the release of particulate matter into the environment. The soot contains carbon monoxide, heavy metals, and carcinogenic dioxins such as benzene and formaldehyde.

Detrimental health effects have been well documented and include asthma, respiratory infections, decreased lung function, malnutrition, cardiovascular disease, and cataracts. Such effects are particularly harmful to the elderly, young children, and the poor, according to researchers.

"I don't think it's an exaggeration to call [an indoor firewood stove] a toxic waste plant," said Kirk Smith, a global environmental health professor at the University of California at Berkeley who has studied the health effects of wood stoves in India and Central America.

A Chilean national health commissioner has warned that poor air quality conditions may increase the risk of swine flu and other current health challenges, with the situation potentially exacerbated in small towns like Temuco.

The Intergovernmental Panel on Climate Change (IPCC), the leading international body of climate scientists, concluded in its 2007 assessment report that burning firewood may affect the global climate as well. When soot settles on light-colored snow or ice, it reduces the capacity of these surfaces to reflect sunlight and contributes to atmospheric warming.

"It doesn't matter if it's a fossil fuel or a biomass fuel, it all contributes to the problem," said Smith, who is researching the use of more-efficient wood-burning stoves for health and climate reasons.

Some scientists have argued that black carbon's warming effect is greater than the IPCC estimated. The particulates are possibly the second most significant greenhouse gas after carbon dioxide and three times more potent in its climate-altering effects, recent studies said [PDF].

Burning firewood as an energy source often contributes to increased levels of deforestation, adding to climate concerns. In Chile, however, forest cover is on the rise, according to the World Bank.

Chile began fighting worsening air pollution in the 1990s in Santiago, the country's capital and home to half the national population. Since then, sulfur and nitrogen pollution have decreased significantly, but particulate matter remains a problem because of increasing population and vehicular traffic.

In Coyhaique, the city that recently ranked the worst in particulate air pollution, 97 percent of residents burn firewood. Firewood in Chile is four times cheaper than paraffin, five times cheaper than natural gas, and seven times cheaper than electricity. Most homes, including Ahumada's, are not equipped for other types of heating systems and are poorly insulated.

In Temuco, where 85 percent of residents burn firewood, the government began measuring local air pollution levels only in 2002. Three years later, the urban area of Temuco-Padre Las Casas was declared a "zone of saturated pollution." Apart from municipal efforts to promote more sustainable burning methods, no official policies regulate the use of firewood.

"In Chile, firewood actually isn't recognized as a fuel [by the government] despite being the second largest source of energy in the country," said Rony Pantoja, regional technical secretary of the National Firewood Certification System (SNCL), a partnership formed in 2005 between firewood dealers and the government. "There are no policies that modernize and make sustainable [firewood] use.... It gives the impression that this issue doesn't interest [the national government in] Santiago."

The Chilean Senate Committee on Mines and Energy met with SNCL in May to discuss addressing firewood management issues. The partnership with SNCL encourages firewood dealers to sell drier wood, which lessens the release of harmful particulates into the air. For a nominal fee of 200 Chilean pesos (35 U.S. cents), sellers receive an official label that they can display to indicate their firewood's quality. By comparison, a cubic meter of wood costs 15,000-22,000 pesos.

Yet local, regional, and state governments have failed to cooperate widely, Pantoja said. As a result, less than 3 percent of publicly purchased wood, including that used in schools, government offices, and even local health agencies, was certified by SNCL, El Mecurio reported in 2008. A year later, the share has risen to 34 percent, Pantoja said.

SNCL's goal is not to impose binding firewood standards on anyone, but to encourage sellers and consumers to be more aware of the issues and to demand higher quality wood, Pantoja said. He hopes one day to establish a Certified Firewood Supply Center that would help improve poor residents' access to quality firewood.

"There's an important part of the population that doesn't have much purchasing power, those who live practically day to day," Pantoja said. "For them, it's difficult to get quality firewood. We yearn to establish a social supply center for certified firewood, but for this we need the support of more institutions. We can't do it alone."

Both urban and national population growth in Chile have held steady at around 1 percent for several years, and air quality is improving, according to the World Bank. But environmental remediation efforts have been concentrated mainly in Santiago and have only recently spread to secondary cities. Meanwhile, smaller municipalities like Coyhaique and Temuco are among the most rapidly growing urban areas in Latin America and face the greatest sustainable development pressures.

For residents of polluted towns, the pace of politics is not enough. The regional decontamination plan issued by Chile's National Commission of the Environment (CONAMA) allotted 30 million pesos (US$53,250) to help with improving fuel quality, replacing heating technology, and beefing up home insulation. These funds, however, will be dispersed in projects taking place only over the next 10 years.

"I have just enough for water, light, cooking, and buying the things I need," said Ahumada, who lives on about US$266 per month. "CONAMA has promised for two years to help out, but there is no help at all."

Jane Zhou is an intern with the Worldwatch Institute. She can be reached at jzhou@worldwatch.org

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