Athens Air Quality Journal

A journal whose aim is to picture the daily Air Quality (AQ) in Athens.

This post aims at documenting how the atmosphere looks and feels like in terms of Air Pollution, day after day, in our capital. Photographs mostly taken from Filoppapou Hill show the visibility over the city, which is a way of visually depicting how clean the Air is, while a screenshot from an AtmoTube PRO portable AQ Monitor (made at the moment the picture(s) were taken), as well as from our own Purple Air Monitor located in Thiseio, show in real time an Air Quality Score based on the Particulate Matter (PM) concentration in the Air.

The World Health Organization (WHO) updated and tightened the Air Quality recommendations in September 2021, for the first time since 2005. This was long overdue since in these past 16 years a whole lot of evidence has been collected in thousands of scientific studies that clearly show how Air Pollution is still the biggest environmental threat to our lives, which kills 8-9 million people every year (over 16.000 in Greece alone). Nine people in 10 breathe polluted air worldwide. Hence the Air Quality guidelines had to be tightened in order to push governments to take stronger measures to clean up the air we breathe.

The new WHO AQ recommendations are the following:

The major concern for the people of Athens are Particulate Matter (especially PM2,5 but also PM10), Ozone (O3) and NO2. All these pollutants are very high at times in Athens compared to other EU cities. Among 1000 European cities, Athens is No. 71 from the bottom in terms of Particulate Matter PM2,5 pollution, which is a very bad score of course. But it is even worse for NO2 pollution, as it ranks No. 16 from the bottom!

PM2,5 is particularly dangerous because it goes straight into our lungs with every breath we take and from there it passes through into our blood stream, from which it then reaches every organ of the body, leading to a general state of inflammation and to all sorts of related illnesses and eventually death. Ozone and NO2 are highly reactive gases that oxidise (literally “burn”) cells in our respiratory ways and lead to various serious illnesses, such as asthma, etc. See here more info on these pollutants.


13/01-13/02/2022

AQ score = 0-90. Air Pollution is high to extremely high at night and moderate during the day. NO2 is low to moderate.

This past month has been characterized by days with the highest pollution scores for the winter so far, with a few bouts of clean air during days with strong wind.

The average Particulate Matter PM2,5 pollution for the whole month was above 35 μg/m3 in central Athens and above 45 μg/m3 in the northern suburbs, which is more than seven to nine times the levels accepted by the WHO (5 μg/m3). Every night PM2,5 pollution climbs to over 200 μg/m3 and even above 300 μg/m3 in some suburbs, which is absolutely intolerable! Needless to say it, this is due to the massive burning of wood at night for residential heating. Energy poverty is a big problem in Greece, which is one of the most affected countries of the EU in this regards. People resort to burning wood in order to keep warm, although this is a highly inefficient way to warm up a house.

The pollution haze is clearly visible in the first picture below, lingering above the city during a day of high pressure.

There have been only a few days with clean air only, and two of them where on January 24th and 25th when it snowed in the whole of Athens!


12/01/2022

AQ score = 90-98. Air Pollution is low at night and very low during the day. NO2 is low.

What a glorious day! Such a strong, cold NE wind can only give us the best Air we could ever dream of in this big, polluted city! Too bad that the cold puts most Athenians in a “stay in” mood, instead of going out and finally breathe healthy Air!

Let’s just remember that this perfectly clean, healthy Air is what we should be able to breathe every day of the year, not only during the 12th of January. A Particulate Matter PM2,5 average of 5 μg/m3 is what the WHO recommends we have over the whole year, but Athens has more than four times that number.


11/01/2022

AQ score = 80-98. Air Pollution is low at night and very low during the day. NO2 is low.

Today was one of the best days of the winter in terms of Air Quality. The Air was crispy clean and the typical city smell was gone, replaced by a nice, countryside smell…

It rained again during the night, which along with the E-SE wind helped to quickly disperse the pollutants from the Air. The Air remained clean also during the next night.

An interesting thing happened during the evening. The E wind that blew all day turned to NW and its average dropped to less than 5 km/h from 17:45 til 19:15. During this time, PM2,5 went from around 10 μg/m3 to 35 μg/m3 in just one hour (17:45-18:45). The evening was on track to becoming again a horribly wood smoke stinking night. But then, fortunately, the wind picked up again and later on turned to NE (and got much colder too), and PM2,5 fell to 7 μg/m3 again in about an hour (19:15-20:15). The wind kept on growing in intensity and blew strong all night, keeping the city’s AQ at excellent, low levels. In the morning PM2,5 was lower that 2 μg/m3!

This event shows that the wind in Athens must be stronger than 5 km/h in average and with gusts of at least 10 km/h in order to be able to clean the city’s Air from the big amounts of pollutants that we the citizens produce every day.


10/01/2022

AQ score = 30-90. Air Pollution is very high at night and high during the day. NO2 is moderate.

Airmageddon!

The weather changed during the night. It got about 5 oC colder in central Athens, it rained but not enough to clean up pollutants from the atmosphere. It actually happened that the high humidity trapped the pollutants near the ground, and the complete lack of wind in the morning allowed them to remain in the air for many hours also during the day. This was the worse day of the winter in terms of Air pollution.

But then, at around 13:30 something happened that turned things around: the very weak wind changed from NW to SE, and started blowing stronger. This gradually cleared up the atmosphere starting from the sea side of Athens then moved to central Athens and northwards. At night the Air remained very clean, fortunately.

That’s a rule of thumb for Athens: winds blowing from any direction in the 180o N-E-S wind-rose’s half are excellent Air cleaners, while winds blowing from the remaining wind-rose’s half (S-SW to N-NW) are much less effective at cleaning the Air of the city. Actually, the latter too often act in the opposite way, because they blow the high wood smoke and traffic pollution from the northern and central Athens basin’s suburbs towards the other areas of Athens, which would normally be cleaner.


02-09/01/2022

AQ score = 50-95. Air Pollution is high to very high at night and low to moderate during the day. NO2 is moderate.

These past days have been characterized by very mild temperatures, with lows around 12oC at night and highs up to 19oC during the day, and high humidity. There was a nice wind during the day that cleared the nightly pollution away, which was anyway not as high as during some of the previous week’s evening (only on the 9th evening it was very high). Some nights the wind kept blowing, maintaining the city’s night Pollution at moderate levels. Overall, these past days have confirmed the impression that, until now, this winter we are enjoying quite a better AQ in Athens compared to the previous years, with the exception of a few days and several nights. The truth is that we haven’t felt the cold yet. Temperatures are quite high for the season, and this should worry us, if we think of the climate crisis…


01/01/2022

AQ score = 25-75. Air Pollution is very high at night and moderate to high during the day. NO2 is moderate.

The traditional New Year’s Airmageddon!

Fireworks = very high Air Pollution. That’s unescapable.

Needless to say it, New Year’s Eve brought back very high levels of Air Pollution in Athens. I must say that we actually had a relatively clean December this winter, fortunately, because there was almost always wind, so the hope was that also last night the wind could clean up the firework’s smoke pollution, along with the usual wood smoke. But it didn’t happen. The wind stopped yesterday afternoon, and didn’t pick up again today, so the smoke lingered over the city for the whole night and day.

Particulate Matter PM2,5 went to almost 400 μg/m3 in the central part of the plain at midnight, and they were already above 150 μg/m3 before because of the wood smoke. During the day they went only briefly below 40 μg/m3 in the same area. But in other parts of Athens on the periphery they managed to get lower than 20 μg/m3.


29-31/12/2021

AQ score = 65-95. Air Pollution is moderate to high at night and low to moderate during the day. NO2 is low to moderate.

The wind changed into a NW direction these days. It was not cold though, and temperatures kept being over 10 oC also at night.

Like during the previous days, the air was clean during the day and only moderately polluted at night because of the wind. Only the “problematic” parts of the city (the central part of the Athenian plain and the northern suburbs) had higher pollution, both at night and during the day.


26-28/12/2021

AQ score = 80-95. Air Pollution is low to moderate at night and low during the day. NO2 is moderate.

On the 26th the weather changed. The wind turned to S-SE and the temperatures increased to up to 19 oC during the day and 14 oC at night. This wind is a blessing for Athens in terms of Air Quality in winter. This is because the higher temperatures mean that fewer wood stoves are lit in the evening, and the air coming directly from the sea is cleaner to start with. Rain fell on the 28th afternoon and evening.

As a result, the concentrations of Particulate Matter PM2,5 dropped to 3 μg/m3 during the day and 10-15 μg/m3 in central Athens at night. Nevertheless, as usual, in the central and northern parts of the Athenian plain wood smoke pollution was quite higher at night than in the rest of the city. In Thiseio (central Athens) we could actually feel the smell of clean air, as opposed to the strong stench of wood smoke and car exhaust of the previous days.

Again, on the last PurpleAir map here below it is possible to see how much better the Air Quality of the islands is compared to the mainland.


24-25/12/2021

AQ score = 40-85. Air Pollution is very high at night and low to moderate during the day. NO2 is moderate.

Airmageddon!

Christmas is usually one of the most polluted day of the year, not only in Greece but across most of the (Christian) Northern Hemisphere. People simply feel in the mood of lighting a fireplace in front of which is so nice to exchange presents…

In Greece presents are actually traditionally exchanged at New Year, not a Xmas. Nevertheless, today was no exception and we still had the traditional Xmas Airmageddon in Athens – and allover the country. The pollution champion was again the city of Agrinio, whose PM2,5 concentrations surpassed 400 μg/m3 in the evening! Athens was not so far back, with concentrations going over 200 μg/m3 in many locations and even above 300 μg/m3 in a few. There had not been so much smoke in the city so far this winter.

During the daylight the air was, for a brief moment, much cleaner.

The contrast with the cleanest locations of the country is extreme. Tinos, Syros, Skyros, Limnos, E Crete, all enjoyed clean air with less than 10 μg/m3 of PM2,5 while at the same time the whole mainland was literally chocking in a huge cloud of wood smoke. These islands simply remind us that Air Pollution, with all its cancer and other deadly illnesses tag attached, is there because of our poor choices in warming our homes and moving around on polluting vehicles. If we decided to completely stop burning fossil fuels and wood we could all enjoy the air of Tinos and Skyros overnight! Think about it.


20-23/12/2021

AQ score = 50-90. Air Pollution is high at night and low to moderate during the day. NO2 is moderate.

The weather was still quite cold for the average Athenian during these days… A moderate N-NE wind blew during the day and dropped at night but never completely. The result is that the AQ of the city was quite satisfactory during the day, but not so good at night, although never as bad as the night of the 18-19 December.


19/12/2021

AQ score = 0-85. Air Pollution is extremely high at night and low to moderate during the day. NO2 is high.

Airmageddon!

The cold NW wind kept the Air Quality at very good level during the night between the 18th and the 19th and during the whole day. But it dropped in the afternoon, unfortunately. people turned on the wood stoves and fireplaces en masse, and as a result the night between the 19th and 20th became the worse of the whole winter so far. Not only in Athens, but in the whole Greek mainland (as during the previous weeks, the islands showed a far better AQ, fortunately for their inhabitants). In Thiseio (central Athens) the PM2,5 concentrations climbed to over 100 μg/m3 for the first time this winter (first Purple Air chart here below), and in Nea Irakleio they went to over 250 μg/m3.

These PM2,5 concentrations are highly toxic, and a new study conducted right here in Athens by Greek scientists shows that wood smoke accounts for almost half the annual carcinogenic potential of the city’s Air Pollution. This means that a large number of cancer cases in Athens are due to wood smoke-related high PM levels!!! The authors call for immediate action to reduce residential wood smoke emissions in urban areas!


18/12/2021

AQ score = 80-95. Air Pollution is low to moderate at night and low during the day. NO2 is high.

A strong, cold NW wind kept the air clean both during the day and night. Nevertheless, the wood smoke smell was still strong at night; but since it couldn’t stagnate over the city, the PM2,5 concentrations remained low to moderate.


17/12/2021

AQ score = 50-90. Air Pollution is high at night and moderate to low during the day. NO2 is high.

After the worse night of the winter in terms of Air Quality because of the cold and windless day of yesterday (not only in Athens, but in most of the Greek mainland), fortunately a NW wind picked up again today at around 10:30, which improved the AQ a bit. But it never got to the good levels of the previous week. And, in the evening, the Airmageddon kicked in again…


16/12/2021

AQ score = 40-80. Air Pollution is high at night and moderate during the day. NO2 is high.

Cold + no wind = high air pollution in Athens, with no exception. If the huge amounts of Air pollutants produced by wood and oil burning and by vehicle traffic have no way to leave the city, then the Air Quality of Athens falls to very bad levels. We can’t get away with that, it’s like a rule of a thumb.

Central Athens and even locations like Papagou and Vouliagmeni (10km south of the city centre, along the sea coast, which enjoys some of the best air of the mainland) had PM2,5 Air Pollution levels that went above 50 μg/m3. But in some northern suburbs, PM2,5 reached levels of over 200 μg/m3, which is toxic. All this thanks to wood burning.

Authorities must finally do something and act in order to help citizens reducing the amounts of pollution they create in order to heat up their homes and move around the city. Authorities have a huge responsibility for the dire state of Athen’s Air Quality. They never took the problem seriously.


15/12/2021

AQ score = 60-95. Air Pollution is moderate to high at night and low during the day. NO2 is high.


14/12/2021

AQ score = 60-95. Air Pollution is moderate to high at night and low during the day. NO2 is high.

The cold, NW wind intensified today. It is also the first day this winter that we woke up with a temperature lower than 10 oC in central Athens.

The low temperature meant that more people lit their wood stoves and fireplaces last night. Luckily the wind kept blowing at night just enough in order to contain the Air Pollution to lower levels compared to the night before.


12-13/12/2021

AQ score = 60-95. Air Pollution is moderate to high at night and low during the day. NO2 is high.

Although the strong SE wind calmed down and changed direction into a light and colder NW wind, the Air Quality of Athens was still excellent these couple of days thanks to the cleansing from the previous days.

Needless to mention it, the fairer wind meant that the AQ of the city suffered in the evening, when the Particulate Matter PM2,5 concentrations suddenly went up tenfold in the suburbs of the city where fireplaces and wood stoves are too many. In other places the AQ remained much healthier – see how big the difference was in the second PurpleAir map here below.

The temperature was mild on the 12th, reaching 17-18 oC in the afternoon, and colder on the 13th (max 12 oC).


11/12/2021


AQ score = 80-90. Air Pollution is low to moderate at night and low during the day. NO2 is high.

Rain + strong SE wind all day = Clean Air!

06-10/12/2021

AQ score = 70-96. Air Pollution is low to moderate at night and low during the day. NO2 is high.

These days, first a strong, warm SE and then a colder NW wind kept the Air Quality of the city at satisfactory levels during the day, and in part also at night. It also seems that the energy crisis that makes all sorts of heating fuels more expensive this winter has been helping to keep a more healthy Air Quality in the city so far. People also seem to turn on fewer wood stoves and fireplaces at night, fortunately. And the strong winds that blow once from the south, once from the north since a couple of weeks now are helping to blow away the smoke from the heating systems but also from the traffic. It is a fact that traffic-related Air Pollution is way less intense this winter compared to the past summer. The wind is really an important factor that keeps the Air of Athens cleaner than in other cities of the mainland in winter, oddly enough…


03-05/11/2021

AQ score = 45-85. Air Pollution is high at night and low to moderate during the day. NO2 is high.

These couple of days the strong wind of the previous week weakened to a weak NW wind. This was still strong enough in order to clear up the air during the day, but not at night. Interestingly, from the PurpleAir maps of these days here below it is possible to understand where the biggest AQ problem of the city lies: right in the centre of the Athens plain, and in the northern suburbs. The central part of the plain is the least developed part of the city, where people use wood for heating their home out of necessity – they are the energy poorest community. They use old wood stoves – not fireplaces and burn any kind of wood. In the northern suburbs live the richest part of the community, who don’t really need the wood for heating but just to “embellish” their lifestyle. They have nice, cosy fireplaces and energy-efficient stoves instead of older wood stoves. Both poor and rich have no idea of the serious AQ problem they create in the whole of the city. If you tell them, the poor yell at you that they have no other option, and the rich yell at you that they just spent thousands of euros in order to install the latest fireplace that is of the finest quality and that they were told it doesn’t pollute at all, so they are perfectly entitled to use them as they please and who really cares about the neighbors.


27/11/2021-02/11/2021


Differently from the previous week, this week has been characterized by a strong SE wind that blew also at night in Athens. Needless to say, the Air Quality improved dramatically and even at night there were very low concentrations of Particulate Matter PM2,5, not only in Athens but also in most other Greek cities.

20-26/11/2021

AQ score = 60-90. Air Pollution is moderate to high at night and low during the day. NO2 is high.

These days have been characterized by a general lack of wind at night in Athens (and on most of the country’s mainland). During these days there was only the usual local breeze blowing from SW. As a result, the Air Quality has deteriorated significantly, fact that is well visible both the AQ charts and maps as well as on the second photo. Still, the temperature was not cold enough in order to force people to light their wood stoves and fireplaces en masse, hence the Air Quality remained better than during other colder, windless days.


19/11/2021

AQ score = 50-80. Air Pollution is high at night and moderate during the day. NO2 is high.

Today fell some rain, finally. In the early morning it briefly cleared out some of the persistent pollution accumulated during the past 10 days. Then the particulates concentration grew up again during the day. At night the wood smoke was intense. Yet, a beautiful full moon briefly showed up among the clouds above the Acropolis last night…


17-18/11/2021

AQ score = 70-92. Air Pollution is moderate to high at night and low to moderate during the day. NO2 is high.

Air Quality is still improving in Athens. A NE wind helped with that, but it was not strong enough to clear out the pollution completely.


16/11/2021

AQ score = 70-85. Air Pollution is moderate both at night and during the day. NO2 is high.

Air Quality is gradually, but slowly, improving in Athens, at last.


14-15/11/2021

AQ score = 40-70. Air Pollution is very high at night and high during the day. NO2 is high.

These past two days the particulate pollution was high all day long. On Sunday 14th thousands of participants ran the Athens Marathon breathing concentrations of PM2,5 up to 9 times worse than it should have been – not really good for their health…


12-13/11/2021

AQ score = 40-85. Air Pollution is very high at night and moderate during the day. NO2 is high.

The strong, cold N wind dropped and turned into a weak NW wind. During the daytime, the AQ was around the WHO limit, but at night it drops very low. The nightly wood smoke smell was now very strong in the city and all around the country! People have started to warm up their homes en masse. From now on until next April, this is going to be the “normal” for the country, which will smell of wood smoke in every of its corners.

This toxic winter air is the major culprit for more than 3433 yearly premature death in Athens alone. See the data here.

PM2,5 levels range from 8 to 50 μg/m3. These levels are below the new WHO recommendation for a 24h exposure during the day, but more than three times higher at night.
NO2 was around 80 μg/m3, which is almost three times the recommended level for a 24h exposure.
O3 reached 95 μg/m3, which is right at the limit of the WHO recommended level for a 8h exposure.

10-11/11/2021

AQ score = 75-95. Air Pollution is moderate at night and very low during the day. NO2 is high.

The weather changed and brought a strong, 10 degrees colder N wind. This immediately. blew away the air pollution that had accumulated over the city during the past week. Air Quality improved dramatically in just a couple of hours during the night. Unfortunately the colder weather means that many people are lighting their fireplaces and wood stoves these days. Still, the strong wind does not allow the combined smoke of these thousands of stoves to get too dense over the whole city. Yet, some neighborhoods have higher pollution than others (see the second Purple Air map here below).

PM2,5 levels range from 4 to 20 μg/m3. These levels are below the new WHO recommendation for a 24h exposure during the day, and slightly above at night.
NO2 was around 78 μg/m3, which is almost three times the recommended level for a 24h exposure.
O3 reached 98 μg/m3, which is right at the limit of the WHO recommended level for a 8h exposure.

07-09/11/2021

AQ score = 50-60. Air Pollution is high both at night and during the day. NO2 is high.

The weather is still warm, very humid and windless. Pollutants can’t disperse from the atmosphere and remain trapped within the city. Air pollution is high both at night and during the day.

PM2,5 levels range from 34 to 48 μg/m3. These levels are two to three times higher than the new WHO recommendation for a 24h exposure.
NO2 was around 80-90 μg/m3, which is almost three times the recommended level for a 24h exposure.
O3 reached 100 μg/m3, which is right at the limit of the WHO recommended level for a 8h exposure.

06/11/2021

AQ score = 0-57! Air Pollution is extremely high at night and high during the day. NO2 is high.

Airmageddon!

Today was quite an unusual day for Athens, but also for the whole country. A high pressure system created a generalized temperature inversion situation over much of the country. High temperatures combined with very high humidity (over 90%) covered Athens and much of the lowland in Greece, including many Aegean islands, with a wide layer of fog. If this prompted awe and lots of wonderful photos from allover the country, in regards to Air Quality it is no good news at all!

In fact, the fog acts as a pollutant trap, keeping all the dangerous combustion products close to the ground right where we live and breathe. It becomes then smog, name that not surprisingly is made from the combination of smoke and fog.

Today’s smog in Athens contained concentrations of PM2,5 at around 40-50 μg/m3 during the day, which are around three times the WHO recommended levels for a 24h exposure (15 μg/m3). But then, at night those levels spiked up to over 150 μg/m3! This is because people, despite a warm air temperature, turned on their fireplaces and wood stoves in order to get rid of the high humidity in their homes. As a result we all breathed very toxic air last night. This nightly levels of Air Pollution were actually the highest of the whole 2021, with the exception of the days in August when the air was filled with wildfire smoke.

PM2,5 levels range from 40 to 150 μg/m3. These levels are three to over ten times higher than the new WHO recommendation for a 24h exposure.
NO2 was around 80 μg/m3, which is almost three times the recommended level for a 24h exposure.
O3 reached 103 μg/m3, which is right at the limit of the WHO recommended level for a 8h exposure.

02-05/11/2021

AQ score = 70-95. Air Pollution is moderate at night and low during the day. NO2 is high.


01/11/2021

AQ score = 50-75. Air Pollution is high both at night and during the day. NO2 and O3 are high.

Due to a general lack of wind, today’ Air Quality was the worse of this autumn so far. It’s the first time that we can see these levels of smog over the city since last winter. The worsening of the AQ is very well visible also in the Purple Air chart below. PM2,5 reached values of around 45-50 μg/m3 at night and in the morning, which receded to around 20-25 μg/m3 during the day. Ozone went again above the safety limit, and NO2 is steadily at values around three times the recommended levels.

The worsening of AQ is not restricted to Athens only, but as the Purple Air map below shows very well, it is generalized to the whole country.

PM2,5 levels range from 20 to 50 μg/m3. These levels are three times higher than the new WHO recommendation for a 24h exposure.
NO2 was around 80 μg/m3, which is almost three times the recommended level for a 24h exposure.
O3 reached 113 μg/m3, which is above the WHO recommended level for a 8h exposure.

30-31/10/2021

AQ score = 60-80. Air Pollution is fairly high both at night and during the day. NO2 is high.

The weather has changed again. In Athens we still have a weaker, N wind which is a bit warmer now because it is influenced by a big low depression passing in the southern Mediterranean. Air Quality in the city is lower these days, as the wind is not strong enough to blow away the pollution generated in the city, especially at night. Furthermore, there is some influence of particulate matter coming from further away to the south of the country. Wood smoke smell is increasing in the city.

PM2,5 levels range from 14 to 45 μg/m3. These levels are three times higher than the new WHO recommendation for a 24h exposure.
NO2 was around 70 μg/m3, which is almost three times the recommended level for a 24h exposure.
O3 reached 60 μg/m3, which is within the WHO recommended level for a 8h exposure.

25-29/10/2021

AQ score = 85-97. Air Pollution is low both at night and during the day. NO2 is high.

The N wind has picked up and although it is cooler than during the previous days, it is strong enough to blow away pollutants from the city. Hence we can enjoy cleaner air both during the day and at night these days. Yet, on the Purple Air AQ map it is possible to see the effect of localized pollution due to wood burning in various parts of the city, especially in the northern suburbs and the central part of the Athens plain.

PM2,5 levels range from 4 to 20 μg/m3. These levels can be considered ok by the new WHO recommendation for a 24h exposure.
NO2 was 65-70 μg/m3, which is more than two times the recommended level for a 24h exposure.
O3 reached 60 μg/m3, which is within the WHO recommended level for a 8h exposure.

24-25/10/2021

AQ score = 67-85. Air Pollution is fairly high in the night and ok during the day. NO2 is high.

These couple of days the Air Quality in Athens has fallen. The fair wind turned into a northerly direction and the temperature has dropped. More people started lighting up their heating stoves in their houses at night, and this is becoming visible in the overall AQ of the city.

As the weather is becoming cooler, Ozone pollution is finally starting to get below the WHO recommended levels. It was about time!

PM2,5 levels range from 9 in the day to 45 μg/m3 at night. This is three times the limits of the new WHO recommendation for a 24h exposure.
NO2 was 70-80 μg/m3, which too is around three times the recommended level for a 24h exposure.
O3 reached 70 μg/m3, which is within the WHO recommended level for a 8h exposure.

22-23/10/2021

AQ score = 67-91. Air Pollution is fairly high in the morning and low during the day. NO2 and O3 are high.

These couple of days the Air Quality in Athens has improved thanks to the S wind, which blew away pollutants and brought temperatures of up to 25 degrees in the afternoon. These are like nice, spring days! We woke up with low levels of PM2,5 (around 8 μg/m3), which temporarily increased to 30 μg/m3 at 9:00AM until 10:30-11:00AM. Then the S wind started and the Air Quality quickly improved to good levels.

This phenomenon with a sudden Air Pollution increase in the early morning is something that happens daily since last week. It’s due to two factors: 1. to the morning traffic rush hour but, 2. especially to the warming up of the atmosphere by the sun around 1 hour after sunrise. The warmer, humid air raises and brings along the pollutants that were deposited to the ground as the air cooled during the previous night. The effect is quite impressive, considering that this morning we had a very nice, crispy air at sunrise, but only 1 hour afterwards it worsened by a 4X factor and the smell of dirty air became very obvious. Then as quickly as the phenomenon came, it went away after about 1 hour and the air became clean again for the rest of the day (and evening).

Air Quality week of 17/10/21 – 23/10/21 in Thiseio, Athens showing the sudden increase and decrease of Air Pollution in the morning these days

PM2,5 levels range from 7 to 30 μg/m3, which are half and double the limits of the new WHO recommendation for a 24h exposure.
NO2 was 60-80 μg/m3, which is around three times the recommended level for a 24h exposure.
O3 reached 104 μg/m3, which is above the WHO recommended level for a 8h exposure.

Today we can open our windows for longer periods of time after 11:00AM.


21/10/2021

AQ score = 57-79. Air Pollution is high at night and in the morning and somehow lower (but not good) only during the warmest hours of the day. NO2 and O3 are high. Sensitive people might start feeling some throat irritation and coughing when exposed to these levels of Air Pollution.

Today the Air Quality in Athens has worsened even further. We woke up with levels of PM2,5 at around 30 μg/m3, which increased to 40 μg/m3 due to high vehicle traffic at rush hour until around 11:00. The air was very “heavy” and bad smelling this morning and only after the wind managed to blow away some of the pollution it became better.

As mentioned earlier (see 18-19/10/2021), this is the beginning of the winter “Airmageddon” in Athens (and in Greece in general). This pattern of (very) high air pollution in the night and morning will be the “normal” for the next 51/2-6 months, until mid/end April. The only moments when the air will be less polluted will be when winds will blow strong either from the north or the south. From now on Athens will, once again, be one of the most polluted cities in the whole of Europe.

If we want to be serious about reducing the serious negative impact of Air Pollution on our personal (and of our dear ones) health this coming winter, we should consider at least taking a few measures:

  • Check out the website Purpleair.com often, which shows in real time the Air Pollution in Athens but also allover the world. This site will immediately show you what kind of air we have in the city at any time;
  • Wear N95 masks also outdoors, because they protect also from PM2,5 from traffic and wood smoke pollution, not only from viruses. Wear them especially when walking on busy roads and when you sense the smell of wood smoke in the air;
  • Carefully ventilate your home by opening windows only during the time of the day when outdoor air pollution is at its lowest. Surely don’t open windows at night and in the morning before 10:30 AM. Best time to open them is from 11:30 to sunset. Some days you can open them more often, and some days you should never open them. Again, check out the Purpleair.com website to see what’s best to do.
  • If you do sport activities in the city, you should follow the same principle as with window opening. Jogging in the early morning or at night with high outdoor Air Pollution is very unhealthy! Try to find time during the afternoon for that. Surely, doing physical activities is better for our health than sitting all day on a chair, but doing sports while breathing high Air Pollution is putting you in more danger than staying at home. See an article about physical activity in polluted areas here;
  • Protect your children from Air Pollution!
PM2,5 levels range from 17 to 40 μg/m3, which is up to almost 3x the limits of the new WHO recommendation for a 24h exposure.
NO2 was 60-80 μg/m3, which is around three times the recommended level for a 24h exposure.
O3 reached 110 μg/m3, which is above the WHO recommended level for a 8h exposure.

Today we should not open our windows for longer periods of time. Surely avoid opening them during the morning and at night. Consider using indoor air filters to keep the air in your home at safe, clean levels.

The same applies to outdoor exercise. Avoid exercising in the morning before the wind kicks in and at night. Children should not be allowed to play outdoors with these levels of Air Pollution.


20/10/2021

AQ score = 67-85. Air Pollution begins to be high at night and in the morning and somehow lower only during the warmest hours of the day. NO2 and O3 are high. Sensitive people might start feeling uneasy when exposed to these levels of Air Pollution.

Today the Air Quality in Athens has worsened again. We woke up with levels of PM2,5 at around 20 μg/m3, which increased to 30 μg/m3 due to high vehicle traffic until around 12:00. Only then a low wind started to clean the air to levels of around 12 μg/m3.

Beside local pollution sources, there is also an influx of Particulate Matter in the atmosphere from further away than Greece. Along with a higher air pressure, the result is that today the air feels “heavy”, and those who can discern it, can feel the typical persistent bad air smell that was much less obvious all the previous windy days. Many people in the city surely felt the “heaviness” of the air and had headache today, without knowing why.

PM2,5 levels range from 12 to 30 μg/m3, which is up to 2x the limits of the new WHO recommendation for a 24h exposure.
NO2 was 50-70 μg/m3, which is two to three times the recommended level for a 24h exposure.
O3 reached 120 μg/m3 during the warmest hours, which is above the WHO recommended level for a 8h exposure.

Today we should open our windows for a longer period of time only during the afternoon hours. Surely avoid it during the morning and at night.

The same applies to outdoor exercise. Avoid exercising in the morning before the wind kicks in and at night.


18-19/10/2021

AQ score = 77-91. Air Pollution is above safety levels at night and in the morning and low only during the warmest hours of the day. NO2 and O3 are high.

After the “Ballos” storm has receded, the weather became more stable. Temperatures dropped a few degrees both during the day and night, humidity decreased and the atmospheric pressure rose. This is a prelude to the typical, more stable, sunny weather in Athens that is met during many days in winter. High pressure means that there is low air circulation; often, during the early morning hours, there is actually a temperature inversion, in which the 250m air layer close to the ground is still colder than the air above (due to quick soil heat loss of the previous clear sky night). This colder air is heavier and remains near the ground trapping all the air pollutants from the early traffic hours and from the previous night’s residential heating. Only after the sun has ascended enough to be able to warm up the cold air layer the air pollutants start then to disperse upwards, usually after around 10-11:00AM.

Needless to say, this more stable colder weather that traps pollutants in the city is no good news: from today officially start the “Airmageddon” in Athens. Unfortunately these days will last until mid/end April. The only moments when the air will be less polluted will be when winds will blow strong either from the north or the south. From now on Athens will, once again, be one of the most polluted cities in the whole of Europe.

PM2,5 levels range from 7 to 20 μg/m3, which begins to be above the limits of the new WHO recommendation for a 24h exposure
NO2 was these day between 50-70 μg/m3, which is two to three times the recommended level for a 24h exposure.
O3 reached 120 μg/m3, which is above the WHO recommended level for a 8h exposure.

These days we should open our windows for a longer period of time only during the afternoon hours when the air is clean. Surely avoid it during rush hours and at night.


14-17/10/2021

AQ score = 90-96. Air Pollution is low during both day and night and poses no serious threat to our health. NO2 is high.

These couple of days, the “Ballos” storm has been pouring down huge amounts of rain allover the country. Athens has been flooded, as well as many villages. The rain gauge on our roof in Thiseio measured a record of 159mm of rain per day on the 14th, which I had never seen before. Imagine that Athens has an average of 420mm/year, so around the 40% of that rain fell in one day alone.

Temperatures in Athens are still mild, and no heating has been turned on yet. The result, along with the storm’s “cleaning” action, is that the Air Quality in the city is very good, both during the day and at night.

PM2,5 levels range from 7 to 12 μg/m3, which is around the limits of the new WHO recommendation for a 24h exposure.
NO2 was 50-70 μg/m3, which is two to three times the recommended level for a 24h exposure.
O3 reached 80 μg/m3, which is above the WHO recommended level for a 8h exposure.

These days we can open our windows with little concern, both during the day and at night.

Video of the streams created by the pouring rain on Pnika Hill

10-13/10/2021

AQ score = 70-98. Particulate Air Pollution is within safe limits during the day and poses no serious threat to our health. But NO2 is high. At night Air Pollution is above the WHO limits.

These days, the Air Quality of Athens is relatively good. The weather is still humid and rainy, with a S-SW wind that blows away the Air Pollution generated in the city during the day. At night the wind ceases to blow and Air Pollution builds up, more so in central Athens and less in the periphery.

PM2,5 ranges from 3 to 12 μg/m3 during the day, which is at the limit of the new WHO recommendation for a 24h exposure and up to 25-30 μg/m3 at night, which is above the WHO limits.
NO2 is 60-70 μg/m3, which is more than three times the recommended level for a 24h exposure.
O3 reaches 90 μg/m3, which is within the WHO recommended level for a 8h exposure.

These days we can open our windows with little concern during the day but we should close them after 20:00 PM until the next morning.


09/10/2021

AQ score = 81-92. Particulate Air Pollution is within safe limits and poses no serious threat to our health. But NO2 and O3 are high.

Today, the Air Quality of Athens in the morning was similar to the one of yesterday, but after 14:00 PM it improved to very good levels. It did not rain today, but the weather was still very humid. The light S-SW wind and the warming of the atmosphere began dissolving the humidity and blowing away the air pollutants in the afternoon.

Yesterday’s rain was a blessing for the natural habitats of Athens. Apart from a little rain at the beginning of September, it hadn’t rained for over 4 months, and the extended, extreme heat of this summer put all plants and animals of Attica under big stress. See here below how dry the Olive trees, Aleppo pines and Carob trees around the Acropolis are right now. The leaves have all dried up and the trees are yellow instead of green. Many trees have actually died this summer. This is how desertification starts: the vegetation, put under severe stress by record heat and lack of rainwater, simply can’t cope anymore and dies. First to go are the trees, then the shrubs, until only the hardiest of plants will remain to withstand the new climate extremes.


At 9:00 AM in central Athens:

PM2,5 was 15 μg/m3, which is at the limit of the new WHO recommendation for a 24h exposure.
NO2 was 70 μg/m3, which is more than three times the recommended level for a 24h exposure.
O3 was 90 μg/m3, which is within the WHO recommended level for a 8h exposure.

After 14:00 PM:

PM2,5 was around 6 μg/m3, which is within the new WHO limits for a 24h exposure.
NO2 was 77 μg/m3, which is more than three times the recommended level for a 24h exposure.
O3 was 130 μg/m3, which is above the WHO recommended level for a 8h exposure.

08/10/2021

AQ score = 81. Particulate Air Pollution is close to the safe limits and poses no serious threat to our health. But NO2 is too high.

The day started in a gorgeous way today…

Today, the weather has changed and with it also the Air Quality of Athens. The N-NE wind of the past week stopped blowing, big clouds came in and rain started pouring down, at last. A light S-SW wind is now bringing humid, warmer air to the city, and this weather will remain similar for the next several days. The Air Quality is reduced now because the light wind is not enough to blow the city’s Air Pollution away and the high humidity “traps” the air pollutants in the air. When the rain pours down it clears the pollution away fortunately, but the tendency is in general to have higher pollution compared to last week. We should be concerned especially in the areas of the city that have high car traffic. For example, while on Philoppapou Hill PM2,5 was 17 μg/m3 at noon, just 10 minutes later in Syntagma Square it was 28 μg/m3, which is not good.

At noon in central Athens:

PM2,5 is around 17 μg/m3, which is just above the new WHO limits for a 24h exposure.
NO2 is 82 μg/m3, which is more than three times the recommended level for a 24h exposure.
O3 is 23 μg/m3, which is within the WHO recommended level for a 8h exposure.

Today we should open our windows with some concern and not leave them open for too long, especially if we are close to a busy road.


07/10/2021

AQ score = 97. Air Pollution is low and poses no threat, but NO2 is high.

Today, like during the whole past week, with and AQ Score over 90 the Air Quality of Athens is excellent thanks to the N-NE wind that is still blowing day and night. The wind is constantly pushing the traffic fumes and other sources of air pollution away, while domestic heating has not been started and therefore there is no Wood Smoke in the city yet. As a result the Air is generally clean in the whole city (with the exception of localized situations like close to the main traffic arteries for example). The visibility is excellent and from the Filoppapou Hill it is possible to see more than 20 Km away in all directions.

At noon in central Athens:

PM2,5 is around 5 μg/m3, which is excellent also under the new WHO limits.
NO2 is 60 μg/m3, which is more than twice the recommended level for a 24h exposure.
O3 is 80 μg/m3, which is within the WHO recommended level for a 8h exposure.

Today it is one of those (rare) days in Athens in which you can keep your windows open without being too much worried about putting your health at risk.


06/10/2021

AQ score = 94


05/10/2021

AQ score = 90


04/10/2021

AQ score = 92


03/10/2021

AQ score = 95


02/10/2021

AQ score = 92


01/10/2021

AQ score = 94

Published by cleanairingreece

CleanAir in Greece is an independent site meant to inform the public about the day to day Air Quality in Greece, with advice on how to protect ourselves from the dangers of Air Pollution

2 thoughts on “Athens Air Quality Journal

  1. Why is the Greek Govt. still allowing citizens to use fireplaces in Athens? We are in the middle of a climate crisis
    and yet after all the talk of measures, nothing seems to have changed.

    Liked by 1 person

    1. Thank you Kathy for your comment. Unfortunately this is not a Greek problem only. The wood stove “scam” is about 15 years old now, and it has been growing in most countries. It’s so similar to the diesel scam. “Eco”, “ultra-efficient”, “smokeless” – whatever they call them – wood stoves are sold as a sustainable alternative to burning fossil fuels. Trees are cut to be burnt, then new trees grow up again to re-absorb the carbon that has been released in the atmosphere by the burning process. Theoretically it sounds right, but in reality it does not really sum up like that.
      Anyway, to make the answer short, it’s because of this flawed theory taken as an excuse that nobody stops wood from being burnt in cities and villages. Too many stoves have already been sold, and too many are being sold as we write. And you know that when something becomes too big, then politicians refrain from going against citizens in fear of losing popularity. As simple as that.
      In Greece the ND party has recently released a number of measures that in the coming years will limit the burning of fossil fuels, hence the Air Quality will become better. But nothing has been said about wood burning yet, sadly. Only when Europe as a whole will finally accept that wood burning is not sustainable, then also state members will start doing something about that.

      Like

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