Air quality in Sao Jose dos Campos

Is Sao Jose dos Campos currently a very polluted city?

São José dos Campos, meaning Saint Joseph of the Fields) is a major city and the seat of the municipality of the same name in the state of São Paulo, Brazil. It is situated between São Paulo and Rio de Janeiro in the Paraíba Valley. It is considered to be the first megalopolis in the Southern Hemisphere with over 30 million inhabitants between them. Sao Jose dos Campos alone has approximately 730,000 residents, according to a census conducted in 2020.

Towards the end of 2021, São José dos Campos was experiencing a period of air quality that was classified as being “Unhealthy for sensitive groups” with a US AQI reading of 110. This United States Air Quality Index number is calculated using the levels of six of the most commonly occurring air pollutants, such as nitrogen dioxide, sulphur dioxide, ozone, carbon monoxide and both sizes of particulate matter, which are 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. The only pollutant recorded in São José dos Campos was that of PM2.5 which was 39.2 µg/m³.

This level is almost four times the recommended safe level of 10 µg/m³ as suggested by the World Health Organisation (WHO) as being an acceptable level. Although no amount of air pollution is safe.

When the level of air pollution is this high, the proffered advice would be to remain indoors as much as possible, closing all doors and windows to prevent the ingress of more polluted air. It would be beneficial to operate an air purifier if one is available, but make sure it recirculates the current air without bringing more inside from outdoors. Those of a sensitive disposition should limit their time spent outside and should always wear a good quality face mask if doing so. For up-to-date information about air quality, there is an app available from AirVisual which is downloadable for all mobile devices.

Does the air pollution remain at the same level throughout the year in São José dos Campos?

Air quality is very volatile as it is subject to many external influencing factors such as meteorological and atmospheric changes.

Looking at the figures for 2020, released by IQAir.com it can readily be seen that for January, February and March and November and December, São José dos Campos achieved the WHO target figure of less than 10 µg/m³. February being the best month with a 6.3 µg/m³ reading. The following month of April returned “Good” quality air with a figure of 10.7 µg/m³. For the remaining six months of the year the figures fell into the “Moderate” quality bracket. To qualify for this classification, readings must fall between 12.1 and 35.4 µg/m³.

Records regarding air pollution were first kept in 2019 when a figure of 11.8 µg/m³ was noted which was classified as “Good”. This trend continued into the following year when that reading was 11.5 µg/m³. However, this reading may have been affected by the COVID-19 situation as many vehicles were no longer in daily use because the offices were closed, 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 São José dos Campos?

An unprecedented study carried out by the Municipality of São José dos Campos shows that fires are the main sources of pollution in the city. According to the municipal administration, this type of occurrence puts into the air, per year, around 9.8 tons of carbon monoxide, ahead of other polluting agents, such as road transport (8,200) and industry (4,700). The research took into account mobile pollution sources, such as air transport, landfills and sewage treatment plants. In total, more than 63,000 tons are released into the atmosphere per year.

What can be done to reduce air pollution in São José dos Campos?

The polluted air from Sao Paolo, especially in winter, can reach cities located up to 100 kilometres away, although in lower concentrations than in the vicinity of avenues or industrial plants where it is produced.

Depending on the time of year, 20 to 30 per cent of the pollution, for example, comes from São Paulo. The drier air that came to predominate in winter makes it difficult to disperse the pollutants generated by the 6 million cars, 400,000 trucks and buses and around 30,000 industrial installations in the Metropolitan Region.

Carried away by air masses, the pollutants emitted by cars - ozone formers - leave the capital and participate in reactions promoted by sunlight, which take two to three hours to complete - enough time for them to reach neighbouring cities or settle on the slopes of the mountains. The situation worsens in November, when there are many sunny and cloudless days with not much wind.

Due to deforestation and industrialization, air quality is constantly degrading from year to year. Brazil is working on a series of CONAMA resolutions and national air quality plans to control atmospheric emissions.

Air pollution from industries or factories can be reduced by using public transport to travel, increasing the efficiency of equipment to consume less energy and opting for natural gas as a source of fuel.

What are the health impacts of breathing dirty air in São José dos Campos?

Deaths occur primarily from inhaling gases and exposure to fine particles that penetrate deep into the lungs and cardiovascular system and can cause stroke, heart disease, lung cancer, chronic obstructive pulmonary disease, and respiratory infections, including pneumonia.

Although not easily seen, the tiny particulates that remain in the air after fires—specifically, particles that measure no more than 2.5 micrometres (about 30 times smaller than a human hair) often known as PM2.5 —when inhaled, can cause various damages.

In the short term, exposure can cause difficulty breathing, sore and burning throat, hoarseness, headache, tearing and redness in the eyes, but several types of research already show that the damage goes beyond that: smoke can harm the lungs, the blood vessels and the immune system.