Qualité de l’air à Coyhaique

What is the level of air pollution in Coyhaique now?

Coyhaique, (also spelled Coihaique) in Patagonia, is the capital city of both the Coyhaique Province and the Aysén Region of Chile. As a city, it is less than 100 years old because Chile showed very little interest in the Aysén Region. It is thought to have been founded as late as 1929. According to the 2012 census, Coyhaique had a population of almost 54,000 people. It is rather isolated being surrounded by rivers and high mountains. These peaks are often covered in snow throughout the year which earns Coyhaique the title of the city of eternal snow. However, these mountains protect it from some of the harshest westerly winds.

Towards the middle of 2021, Coyhaique was experiencing a period of “Unhealthy” air with a US AQI figure of 182. This United States Air Quality Index figure is an internationally used set of metrics that is used to determine the level of air pollution at any given time. It can be used to compare several cities, even when they are in different countries. The number is calculated by measuring up to six of the commonly found pollutants in the air. There were just three pollutants which were recorded for Coyhaique which were as follows: PM2.5 - 56.9 µg/m³, PM10 - 109 µg/m³ and sulphur dioxide (SO₂) - 6.4 µg/m³.

With levels such as these, the advice is to close doors and windows to prevent the ingress of more dirty air. Those of a sensitive disposition are advised to remain indoors or if travel outside is unavoidable, then a good quality mask is recommended. It is recommended that all unnecessary outdoor exercise is postponed until the air quality improves. Consider changing the venue to a sports hall or a gym instead. It is advisable to use an air purifier if one is available.

When is the best time of year to enjoy clean air in Coyhaique?

Bear in mind that Coyhaique is in the southern hemisphere and therefore the seasons are opposite to those experienced in the northern hemisphere. During the months of November, December and January, Coyhaique attained the target figure as suggested by the World Health Organisation (WHO) and registered figures of less than 10 µg/m³. In February the air quality was “Good” with a level of 11.3 µg/m³. In March and again in September and October the quality slipped to being “Moderate” with records between 12.1 and 35.4 µg/m³. During April and August the records showed the air quality to be “Unhealthy for sensitive groups” with figures between 35.5 and 55.4 µg/m³. The worst months of the year were May, June and July with “Unhealthy” air. Figures between 55.5 and 150.4 µg/m³ verify it.

Records about air quality have been held since 2017 when the first recording was noted as being 39.3 µg/m³, the following year saw an improvement when the figure was 34.2 µg/m³. In 2019 it deteriorated to 41.4 µg/m³ before a vast improvement in 2020 when it was 33.3 µg/m³.

This 2020 figure could be unusually lower than normal because of the restrictions brought into force due to the COVID-19 pandemic when the use of private vehicles was mainly prohibited and many manufacturing plants were told to cease production until further notice.

What are the sources of all this polluted air in Coyhaique?

The cause of pollution, as it occurs from Rancagua to the south, is the indiscriminate use of firewood as a source of heating. In fact, firewood smoke from residential heating is responsible for more than 90 per cent of fine particulate matter (PM2.5) emissions in cities located between the O'Higgins regions and Aysén. Added to this very serious scenario is the fact that solid biofuels, notably firewood, constitute the third source of energy in the country. With its use, two million homes are heated. According to calculations, the firewood market generates 800 million dollars and provides work, either directly or indirectly for 80,000 people.

Can anything be done to lower pollution levels in Coyhaique?

In recent years it has been news every winter that Coyhaique is the city with the most polluted air in the world.It is a well-known fact that firewood is the main source of PM2.5 pollutants in Coyhaique.

Specific measures are being introduced gradually to lessen the pollution. Specific measures such as cheaper gas, accessibility to paraffin and thermal insulation programs, catalytic filters are all being pursued. It is also now illegal to use more than one wood-burning stove per household.

Everything seems to indicate that there is a consensus that the short-term solution is to increase the heating alternatives, be it gas, paraffin or electricity, by way of improving access (in the case of paraffin) or lowering prices so that more households may have a second option to firewood, however there is also a consensus that non-renewable fossil fuels should not be the long-term solution.

How does this poor air quality in Coyhaique affect human health?

Adverse effects depend, on the one hand, on the concentration and duration of exposure and, on the other, on the susceptibility of the exposed persons. The dose actually received is dependent on minute ventilation.

Children and the elderly are especially susceptible to the effects of pollutants. On the other hand, the presence of respiratory and cardiovascular diseases also increases vulnerability to air pollutants, since these conditions are accompanied by dyspnoea, increased minute ventilation, and difficulty in airway clearance due to oedema, inflammation, limitation airflow or by decreased capacity to mobilise lung volumes.

Air pollutants also contribute to a decrease in lung function and an increase in bronchial reactivity, decrease exercise tolerance and increase the risk of chronic obstructive bronchitis, pulmonary emphysema, exacerbation of bronchial asthma and lung cancer, amongst other effects. . In Chile, since 1980, studies have proliferated that demonstrate the effects of air pollution, especially particles, on daily mortality, respiratory symptoms and consultations. These studies, carried out first in Santiago and later in Temuco, have confirmed the results reported in international publications that have established that for every 50 µg/m³ increase in PM10 levels in 24 hours there is an average increase of about 3 per cent in general mortality. These studies have also detected that an increase in PM10 is associated with an increase in respiratory and cardiovascular mortality.