Qualité de l’air à Puerto Montt

What is the current level of air pollution in Puerto Montt?

Puerto Montt is a port city and commune in southern Chile, located at the northern end of the Reloncaví Sound. It is just over 1,000 kilometres south of the capital, Santiago. According to a census conducted in 2017, the estimated population was approximately 245,902 people.

In September 2021, Puerto Montt was experiencing a period of “Unhealthy” air with a US AQI reading of 155. This United States Air Quality Index number is calculated using the levels of six of the most prolific air pollutants, such as nitrogen dioxide, sulphur dioxide, ozone, carbon monoxide and both sizes of particulate matter, being PM2.5 and PM10. It can then be used as the metric when comparing air quality in other cities around the world. If data is unavailable for all 6 pollutants, a figure can still be calculated by using what figures there are. In this case, the only figure recorded was for PM2.5 which was 63 µg/m³. This level is over six times the recommended safe level of 10 µg/m³ as suggested by the World Health Organisation (WHO).

With pollution at this level, the given advice would be to stay inside and close all windows and doors to prevent the ingress of more polluted air. The use of an air purifier would be advantageous if one is available, but remember to set the air intake to recirculate the existing air and not bringing more air in from outside. Those who are sensitive to poor quality air should avoid exercising outside until the quality improves and if venturing outside is unavoidable, then the wearing of a good quality face mask is essential. For up-to-date information about air quality there is an app available from AirVisual which is downloadable for all mobile devices for free.

Does the level of pollution stay the same throughout the year in Puerto Montt?

Looking back at the figures released by IQAir.com for 2020, it can be seen that the months of January, February and March achieved the target figure of 10 µg/m³ or less as recommended by the World Health Organisation (WHO). The respective figures were 6.5, 6.8 and 8.9 µg/m³. The month of November provided Puerto Montt with ”Good” quality air with a reading of 11.9 µg/m³. For the remaining seven months of the year the air quality was classified as being “Moderate” with figures between 12.1 and 35.4 µg/m³. The best month being October with a 17.9 µg/m³ reading and the worst was May with a reading of 33.7 µg/m³.

Records regarding air quality were first kept in 2017 when a level of 29.6 µg/m³ was recorded. A slight improvement was seen the following year with a figure of 22.6 µg/m³. This figure declined in 2019 when the recorded level was seen to be 26.4 µg/m³, however, a noticeable improvement was seen in 2020 when the recorded figure was 18.9 µg/m³. This reading may have been affected by the COVID-19 situation as many vehicles were no longer in daily use in an attempt to halt the spread of the virus. Many factories and non-essential production units were also required to close which removed their emissions from the atmosphere.

Is there a main source of air pollution in Puerto Montt?

Most of the air pollution in Puerto Montt comes from the combustion of firewood in residential homes. A lot of the pollution is created by burning wood that has not been sufficiently dried. It is recommended that dry wood (less than 25% humidity) is always used to alleviate this problem and can easily be obtained from established merchants.

Due to the high levels of PM 2.5 pollution, earlier this year the Health Seremi of the Los Lagos region decreed the first Environmental Emergency for the communes of Puerto Varas and Puerto Montt.

Wood burning contributes seven times more pollution than light vehicles. Experts say that if only wood burning were banned and controlled, smog would drop 40 per cent and the level of pollution would drop.

It far exceeds others, such as pollution from off-road transport (tractors), which contribute 958 tons per year; trucks and buses, which emit 600 tons, or cars, which in total (considering gasoline and diesel) are responsible for 298 tons per year of PM 2.5. In other words, firewood contributes seven times more of this pollution in the Santiago basin.

What can be done to reduce air pollution in Puerto Montt?

The operation of open-hearth chimneys within the urban radius is prohibited throughout the day. Burning is prohibited within the urban radius and within a radius of 5 kilometres, throughout the day. Also, the prohibition of the emanation of visible fumes from residential units of firewood, wood chips or charcoal within the urban radius, between 18:00 and 24:00 hours.

According to estimates by the Ministry of the Environment, the ban on firewood would reduce residential emissions by 90 per cent and in transportation, the restriction could do so by 80 per cent.

What are the health impacts of breathing dirty air in Puerto Montt?

Regarding particulate material, coarse particles, whose size is between 2.5 and 10 microns, come from the suspension of dust, earth or other materials from the road, agriculture, mining, wind storms or volcanoes. Meanwhile, fine particles of less than 2.5 microns come from emissions from combustion processes, such as gasoline, diesel, firewood combustion and industrial processes. The latter are the most dangerous for people's health, since they are capable of entering the respiratory system and from there into the bloodstream, and can also affect the cardiovascular system.

Air pollutants produce inflammation that alters the defence mechanisms of the respiratory system, which ultimately causes a response in the airway, a situation that can trigger complications in patients with chronic respiratory disease such as bronchial asthma, chronic obstructive pulmonary disease (COPD), and diseases derived from tuberculosis and pulmonary fibrosis, amongst others.

The following acute effects have been studied in children; inflammation of the airways, bronchial hyperresponsiveness, respiratory symptoms such as irritation of the nose and throat, emergency visits, hospitalisations and temporary alterations in lung function have been demonstrated. In this context, various studies have shown that fine diesel exhaust particles (PEDs) increase the pro-inflammatory activity of microbial components, and this may have consequences if a child comes into contact with an infectious agent. This partly explains why children who live in urban areas have a higher incidence of respiratory infections than children who live in rural areas or the countryside.