Safe Air in Schools

Schools have started for at least a month in most countries. We, as parents, are excited to have them enjoy in-person school life. But fears of COVID-19 linger in the back of our heads. Children are in closed environments most of the day. Scientists have said “masks + ventilation” are the key most important measures to control the spread of COVID-19 in schools. Masks can be controlled and teachers are on top of this. But how can school administrators know ventilation is adequate? how can parents be reassured about safe air in our children classrooms?

At meo we designed a new deviceto answer this problem. We are happy to announce the launch of ‘meo mini‘: the ideal device to monitor safe air in schools. This solution is an air quality safety system which includes a monitoring device, and a software solution to ensure safe, healthy and productive spaces.

How does it work?

Through air quality monitoring, meo mini monitors ventilation efficiency in an indoor space. It alerts of any issue through light notification and email, before it becomes a problem. It tells you exactly which classroom or space needs to have windows and doors open to flush risk away, and how much time those openings are required. Daily alerts and monthly statistics provide reassurance for teachers and parents.

How is the device?

Meo mini is a small device that can be placed anywhere in a classroom walls. It’s a Plug&Play solution with an embedded sim card using its own LTE network, which allows installation simplicity and high security. Powered through battery or USB-C.

How can a user access the air quality measurements?

A visual color coded display on the device is the first step of alert to know if ventilation is occurring in a closed environment. The device also connects to a system platform that sends notifications and alerts with options for remedial actions to be taken. The platform can also be accessed by administrators to identify patterns in time and root causes. This feature empowers them to take actions to reduce their exposure sustainably, and bring wellness into their space.

With Meo mini, air ventilation can be monitored and both parents and teachers can rest assured the classroom is a safe environment!

More than a monitor, an air quality safety system

As life is adapting to a new “normal”, schools need to stay open to allow children to build their own identity through learning and social interactions.

Parents, teachers and students will go through tremendous anxiety thinking about the airborne risks that may await them in school. In order to reduce Covid risk in classrooms and any indoor places, it is necessary to check they are not underventilated.

Showing how fast issues were solved…

Meo air analytics newest monitor “mini-meo” will be available from September 2021. It ensures air safety in the premises, with alerts as soon as problems arise, and dedicated advice to remediate. You can then communicate and reassure staff, students and parents on air quality for any time since the installation of the monitors.

“Mini-Meo” is specially designed with dashboards to objectively reduce Covid-related risk:

  • Get alerts as soon as air quality presents a health risk
  • Ventilate and see your action give immediate results
  • Access historic data to understand periodic patterns
  • Reassure stakeholders on the air safety of the premises

How to reduce Covid risk?

Covid risk is higher in indoor places where the air is not enough renewed. [link to research]

Virus risk can be reduced with proper ventilation levels. They can be monitored through dedicated KPIs (Key performance Indicators) to adjust BMS (Building Management System) rules to ensure air circulation and appropriate ventilation.

It is easy to install, cyber-secure and the purchase of the monitor includes a 3 year data plan (sim card with data included) with wide access to air analytics!

Subways: Concerning Air Quality, but Solutions are Available

As some countries start slowly to go back to work in offices, it’s probably time to think about the air we breathe in subways. We have learned so much about indoor air quality throughout this pandemic that we should probably check few things in our local subway system to assess its air quality. From studies conducted few years back we know that in average people spend 30-40 min in metros, time in which they are exposed to harmful air pollutants from components in the subways and from air pollutants that are brought in through the ventilation system.

An assessment from 2017 that looked at more than 160 studies from 20 countries found that airborne bacteria, particulate matter, aromatic hydrocarbons and carbonyls were the main pollutants in all metro systems. It’s estimated that more than 120 million people used the subway every day before the pandemic. In fact, the use of metros have been encouraged as a way to reduce outdoor air pollution, it has always been the smart, efficient and environmentally friendly way to commute.

However, studies have shown that the exposure to air pollution from point A to point B is higher when done in a subway than walking or in trams, but lower than in buses. Studies have also shown that some stations have very poor air quality but others have demonstrated to comply with the European PM2.5 air concentration limits. Suggesting it is possible to have stations with acceptable air quality. It is not clear if the PM prevalent in subways is more toxic than outdoor PM and very little information is out there on the long-term effects of subways’ air quality.

In essence, the source of subway PM comes from the train wheels, brake pads, steel rails and power-supply materials. And is affected by the ventilation, outdoor air supply, depth of station, date of construction, train frequency and the existence of screen-door systems.

Comparison between stations with better air quality and those with poorer air quality shows that changes can be made to improve things. For example,  changes in train speed, type of ventilation, the implementation of screen-doors and the use of air purifiers are all positively impacting air quality in subway stations.

If some stations can  have acceptable air quality, this means that constant air monitoring can lead to effective changes that will benefit  those millions of subway users.

Open Edition Journals- Commuting by subway? What you need to know about air quality

Science Direct- Air quality inside subway metro indoor environment worldwide: A review.

Simple Measures Can go a Long Way in School Air Quality

The importance of air quality in schools has been much explained even before the pandemic. The schools have a combination of furniture, material for activities like painting and the fact that 20 to 30 kids breathe he same air for extended periods of time. In fact, children spend a third of their day in school, many in a single classroom. Moreover, often schools are in close proximity to highly polluted areas like avenues or cross roads.  All these conditions combined with the temperature and humidity stuff the air with harmful particles and serve the proliferation of pathogens. In France, a study conducted in 2019 by the association RESPIRE showed that 100% of schools and kindergartens have PM2.5 measurements above the WHO recommended level and 1 in 4 are located less than 50 meters from a source of pollution.

After the 2020 shut down of schools across the globe for diverse lengths, more care has been put into the air quality in schools to resume in-person education. Social distancing and distance between desks in classes is a key aspect for schools to be allowed to re-open. However, it is now known that ventilation and air filtration is essential.

The CDC recommends to keep doors and windows open (if safe) and even encourages the use of fans to couple this and create air circulation. Ideally, outdoor air in-flow and outdoor air out-flow should be to reduce the concentration of virus particles in the air.

These times call for close monitoring of air quality in schools. For those with Heating, Ventilation and Air conditioning (HVAC) systems, it is essential to service them, to ensure ventilation is happening and to enhance air filtration. However, if HVAC systems are not in place, ventilation with the use of air flow that induces indoor and outdoor air circulation is a must and air filtration will further dilute any possible pathogen. The New York Times commissioned a simulation of air flow in a classroom where masking and table distancing is in place, it is clearly shown how simple measures like opening windows and placing filtration systems in the center of the classroom dilutes the existence of pathogens in the air making the classrooms much safer.

Spaciency-Focus Sur la Qualité de l’Air dans les Creches et les Ecoles Primaires

CDC- Ventilation in Schools and Childcare Programs

The New York Times- Why Opening Windows is a Key to Reopening Schools (subscription required)

Unexpected Air Quality During this Pandemic

Throughout the year 2020, we heard many reports from cities across the world showing how clear the sky was. In Delhi, in London, in San Francisco, in Los Angeles and many more. The normal conclusion most of us had was that halting human activity and transportation had a dramatic effect in clearing the air. Most of us thought a move to electric mobility will do the trick to reduce air pollution.

However, scientists dedicated to study air pollution saw a different reality. That portrays the complexities of air pollution. For 20 years Francesca Dominici from the Harvard T.H. Chan School of Public Health has been studying the effect of air pollution on health. She and her colleagues created a platform that links data on the health of Americans. They used Medicare and the quality of the air wherever they live. In the past, the amount of data they had and the time-span of it led them to clear conclusions.

The scientific evidence

  • Pollution could be linked to higher death rates. Even when air quality was at the level known as ‘national standard’, meaning the standard level does not seem to be safe.
  • Hospitalizations for kidney failure, septicemia where up every time pollution was up. Which supports evidence that PM2.5 can permeate and affect internal organs.
  • Air pollution, both indoors and outdoors, is harmful at lower levels than acknowledged by authorities. It affects many parts of our bodies. The toll on the body of air pollution affects all the body’s essential systems: the brain (Alzheimer and cognitive decline), the nervous system (Parkinson’s and neurodevelopmental disorders), the cardiovascular system (coronary artery disease, strokes, heart attacks, blood clots), the respiratory system (COPD, asthma, lung cancer), endocrine system (obesity, diabetes), the reproductive system (diminished fertility, low birth weight, premature births); in addition to colon cancer, bladder, kidney and stomach cancers.

Air quality in pandemic times

When the pandemic struck in 2020 and countries started imposing lock-downs and reducing mobility. All scientists that had worked on air pollution took this opportunity to understand what happens when traffic is dramatically reduced. The answers where not as straightforward as we would have expected. Each country and even each city had different reactions. In some cities NO2 and CO2 levels went down but ozone went up.

In Italy, for example, it was observed that during lock-down air pollution did not go down as expected with cars and transportation industry halted. It turned out the PM2,5 levels were only 16% lower than in 2019. In fact, the highest polluter in Europe, parts of the US, Russia and East Asia is agriculture.

Ballistic role of PM2.5

Joshua Apte, an atmospheric chemist at the University of California, Berkeley said: “I was really struck by how little the PM2.5 composition seemed to have changed” in Delhi, he says . “We were looking for a smoking gun” of emission changes, he says, “but there wasn’t one”. “Just as PM2.5 levels didn’t fall dramatically, their chemical composition didn’t shift radically”.

Nonetheless the association between air pollution and mortality and disease held true:

  • During the onset of the pandemic viral death rates were higher in those places with higher PM2,5. Bodies exposed for many years to PM2,5 were more susceptible to the virus.
  • Worldwide particle pollution was responsible for 15% of COVID deaths and for 27% in East Asia.

In China, improved air quality due to factory closures during lock-down saved between 9,000 and 24,000 lives. For scientists in this field it is very clear that better air saves lives. Worse air translates into more asthma attacks, more heart attacks, and simply more deaths.

Although the basic link between air pollution and death and disease held true during the pandemic, many new lessons were learnt. Air pollution complex composition should take into account traffic, agriculture, industries and many more sources of contaminants.


Chemical&Engineering News – COVID-19 lock-downs had strange effects on air pollution across the globe

Science News – What the pandemic can teach us about ways to reduce air pollution

National Geographic – Air pollution kills millions every year, like a ‘pandemic in slow motion’

Did you know the air quality in your car may be worse than outside?

Research in London conducted by Enviro Technology Services using the Air Quality Monitoring vehicle –also known as the ‘smogmobile’, has shown that NO2 was on average 21% higher inside vehicles than outside. Dr. Ben Barratt, air quality researcher at Kings College in London, mentioned that these research findings add to the already existing evidence that vehicles do not protect against air pollution. In fact, he called on the need to better understand the health effects of this high pollution exposure for those who spend vast amounts of time in a car, such as taxi and bus drivers. Another recent research by El-Fadel M and Abi-Esber L also showed that exposure in-vehicle to VOC and PM2.5 is high, that the ventilation mode greatly contributes to the exposure,  that 3 out of 6 cars have instrusion of own engine fumes and that air pollution was higher inside new cars than outside. In fact, taxi and bus drivers have 5 times more exposure to bad air quality than people who work elsewhere.

The new car smell

A number of studies have been conducted in the past 10+ years on Volatile Organic Compounds (VOC) inside new cars. In fact, that attractive ‘new car’ smell, is off-gas derived from a mix of materials used in the treatment of leather, dashboards and seats, in addition to the glues.

There can be 50-100 VOC individual compounds in any given car, including bromine, chloride, phtalates, lead and heavy metals. All of which, according to Jeff Gearhart -research director at the Ecology Center, have been linked to cancer, birth defects, allergies, liver toxicity and impaired learning.New cars have VOC concentrations above the indoor permissible levels, but luckily they fade away in the first 6 months of a car’s life.Heat can increase these concentrations considerably.

PM2.5, mould spores, microorganisms and others

In addition to VOCs, studies which have been conducted to look into the air quality inside the cars, have found that there is also high concentration of PM2.5 and higher concentrations of carbon monoxide, benzene, toluene and fine particulate matter than in road-side monitoring stations. Moreover, studies have also found high concentrations of mould spores and bacterial endotoxins, which may induce major respiratory symptoms, allergies and are of concern to asthmatics.

How can we protect ourselves?

Ensure car ventilation to decrease the inside VOC at a faster rate, specially in the first 6 months of a car. Either have the windows down or use air conditioning regularly.

– Use air re-circulating options when stuck in traffic to avoid excessive amounts of engjne exhaust fumes coming into the car.

– Use air conditioning to control humidity and reduce mould spores and bacterial microorganisms.

– Avoid accumulation of dust, moisture/mould or residual cigarette smoke.


Science Direct – Indoor to outdoor air quality associations with self-pollution implications inside passenger car cabins

Explorations of everyday chemical compounds – The Chemicals Behind the ‘new car smell’.

Ecology Center – New Ecology Center guide to toxic chemicals in cars helps consumers avoid a major source of indoor air pollution

NIH – Car Indoor Air Pollution

Breathe better, increase your productivity!

Productivity across all levels of employment matters and business leaders struggle to make sure it is optimized by investing in training, team building, office settings, freebies and many other proven strategies. However, 15 years of research has shown a close link between air quality and productivity that are the basis for green buildings and better indoor air management.

For many years we have known about the sick building syndrome (SBS), which are the common ailments that arise from time spent in a particular building and being exposed to poor ventilation or air filtration, outgasses from building materials, volatile organic compounds (VOC) and molds. Common ailments resulting from SBS are: headache, dizziness, nausea, eye, nose or throat irritation, dry cough, itchy skin, poor concentration, fatigue, voice hoarseness, allergies, cold, increased asthma and flu-like symptoms. And it all escalates to affect our congnitive capacity and productivity. So efforts to reduce both indoor and outdoor air pollution are actually investments in productivity, human capital and economic development.

The earliest known research on air quality and productivity dates back to 1999. Since then many studies on packers, call centers, farmers and even football players have confirmed that poor air quality has a negative effect on productivity, both indoors and outdoors.

In 2011, the National Bureau of Economic Research looked at farm workers output and ozone levels. They found that a decrease of 10ppb in Ozone concentrations increases worker productivity by 4.2%. Overall the research found that even at lower levels of Ozone than the standard, there were negative impacts on productivity and its strict regulation would yield benefits in health, productivity and possibly other areas. This was followed in 2014 by a research at Columbia, the University of South California and the University of California-San Diego where researchers looked into the effect of PM2.5 on pear-packers in California. It was found that just a 10 unit increase in PM2.5 decreased productivity by approximately 6% and that productivity is affected even below US standards. Moreover, Harvard University researchers recently assessed the effect of air quality in knowledge workers, those who are indoors mostly in front of a computer throughout their work day. They analysed Ctrip productivity in China against indoor air quality and found that workers are 5-6% more productive when air pollution is 0-50 AQI compared to 150-200 AQI. In a separate research by Harvard and Syracuse University, researchers looked into VOCs, CO2 and productivity. In addition to confirming the negative effect of air pollution on cognitive function, they specifically found that the greatest change (up to 15%) was observed in those cognitive functions involved in crisis response, information usage and strategy.

This body of research has shown how important it is to look into ways to improve indoor air quality. John Mandyck, chief sustainability officer for the NYSE listed United Technologies Corporation (UTC) said:

So what can we do with all those buildings that are old or just not green?

  • Control biological contaminants such as bacteria, viruses, fungi (including molds), dust mite and pollen. These may result from poor maintenance and housekeeping, water spills, inadequate humidity control.
  • Control chemical pollutants such as tobacco smoke, emissions from products, new furnishings, building materials or cleaning products.
  • Control particles. Particles are solid or liquid substances of dust or dirt from outdoors or other activities such as printing, painting or operating equipment.


  • Make sure ventilation is adequate and not obstructed.
  • Make sure the air is filtered to reduce particles.
  • Make sure to use safe cleaning products and best practices for machine operation.
Know your indoor air quality, control possible pollution sources, implement measures to improve air quality and make sure you are providing the best environment to nurture productivity!


NIH – The Sick Building Syndrome

Harvard Business Review – Air Pollution is Making Office Workers Less Productive

INSIDER – The pollution outside your office window affects your work.

EPA – An Office Building Occupants Guide to Indoor Air Quality

The World – Want better thinking and productivity? Improve the air quality in your office.

What Is It That We All Call Pollution?

Air pollution is becoming more and more present in the news, in casual conversations, in the promotion of products and in many more instances. However, are we all talking about the same thing? What exactly is it that we all call ‘air pollution’?

Air pollution is a mix of natural and man-made substances in the air we breathe which is harmful to our health, it can be any physical, chemical or biological agent that modifies the natural atmosphere. Most sources of air pollution are man-made from mobile sources such as fuel powered motor vehicles; and stationary sources such as factories, refineries, power plants and forest fires. There are also other indoor sources such as building materials and cleaning products. Air pollution, as we now know is present both outdoor and indoor.

Outdoor air pollution:
  • Fine particles (burning of fossil fuels in energy production, coal and petroleum used in vehicles)
  • Gases (sulphur dioxide, nitrogen oxide, carbon monoxide, chemical vapours and others)
  • Ground-level ozone (smog)
Indoor air pollution:

Gases emanating from:

  • Household products and chemicals, or
  • Building materials such as paint, wood, furniture (asbestos, formaldehyde, lead etc)
  • Allergens such as coackroaches, mold, pollen

The World Health Organization (WHO) in 2005 issued the ‘WHO Air Quality Guidelines’ to offer guidance and limits for the most worrying air pollutants because of their threat to human health, their widespread presence in urban areas and their relevance as precursors for other toxic components: particulate matter (PM10, PM2.5), ozone (O3), nitrogen dioxide (NO2) and sulphur dioxide (SO2).

Particulate Matter

Is a mix of solid and liquid (organic or inorganic) particles suspended in the air. It is the pollutant that affects most people and is generally composed by sulphate, nitrates, ammonia, sodium chloride, black carbon, mineral dust and water.

Ozone (O3)

Ground-level Ozone is a major component of smog, formed by the reaction of sunlight with nitrogen oxides (NOX) and volatile organic compounds (VOCs).

Nitrogen Dioxide (NO2)

NO2 is mostly the result of emissions during the combustion process (power generation, heating and engines). It is in fact, a source of nitrate aerosols that form PM2.5.

Sulphur Dioxide (SO2)

SO2 is produced from fossil fuel burning for domestic use, power generation or motor vehicles

Other components generally referred to when talking about air pollution are carbon monoxide (CO), carbon dioxide (CO2) and volatile organic compounds (VOCs), which has greater relevance when talking about indoor air pollution, although also present outdoors.

VOCs are a collection of toxic gases from solids or liquids, that are found in higher concentrations indoors (up to ten times higher). Thousands of products used indoors as construction materials, paints, varnishes, cleaning agents, activities like cooking and many more, are the source of VOCs while being used and while stored. (6) Safe levels / guidelines for exposure to VOCs are not known,, but common sense rules are that they should be kept at low levels to avoid or reduce their negative health effects, which have been well documented.

CO and CO2 are not considered as VOCs. They are both odorless, tasteless and harmful to human health but have clear differences – CO2 occurs naturally in the atmosphere and we can tolerate it in small amounts, whereas CO can cause problems even in low concentrations and is flammable.

  • PM5
    10 μg/m3 annual mean
    25 μg/m3 24-hour mean
  • PM10
    20 μg/m3 annual mean
    50 μg/m3 24-hour mean
  • NO2
    40 μg/m3 annual mean
    200 μg/m3 1-hour mean
  • SO2
    20 μg/m3 24-hour mean
    500 μg/m3 10-minute mean
  • O3 
    100 μg/m3 8-hour mean
    WHO issued these guidelines as a global standard for environmental quality. Each country can adopt the guideline at its maximum standard or take interim standards that better reflect their national balance between health risks, economic decisions, technological capacities and other political and social factors.


NIH – Air Pollution and Your Health
EPA – Pollutants and Sources
WHO – Air Pollution
WHO – WHO Challenges World to Improve Air Quality
WHO – WHO Guideline for Particulate Matter, Sulphur, Ozone…
EPA – Volatile Organic Compounds’ Impact on Indoor Air Quality

We consume, ergo we pollute!

So much is said about the appalling air pollution in China, how its citizens suffer and how only the rich can take adequate protective measures. But so little has been said about how we may all be linked to this pollution, even if we have never set foot in China.

Researchers from Tsinghua University, University of California and other institutions have recently published a paper with very interesting data on how we all bear the brunt of air pollution in China and how pollutants aided by global air currents reach neighboring countries  and affect the health even of those who leave in distant territories. This gives us an idea of the uncontrollable and controllable components of air pollution.

This research looked at PM2.5 (fine particulate matter) in 13 regions across 228 countries, and found that 12% of premature deaths (410,000) globally result from pollutants emitted in a different country, but which are often moved around by global wind conditions. While this result shows us how difficult it is to run away from air pollution that sees no real borders, it definitely makes us see the relevance of monitoring air quality regardless of how far we live from sources of pollution.

At the same time, this study explains how we all bear the brunt of air pollution in China and other countries of Asia. In fact, 90% of air pollution-related global mortality comes from power stations, airplanes, shipping and factories. All elements that constitute global trade. The ever-expanding nature of markets have made cheap products that flood western markets, the basis of a considerable amount of pollution in the East: China, India, Indonesia etc.

Cheap products are produced in Asian countries for a number of reasons – cheap labor and a lack of environmental regulations, which means that the process of production is highly contaminated and contributes to air pollution not to mention water or soil contamination. In addition, these products are produced far away from the place of their consumption so shipping and airplanes need to be heavily used to freight them to their end users.

Dr Qiang Zhang, one of the researchers, revealed that in 2007 consumption in the United States and Western Europe was tied to 110,000 premature deaths in China. In fact, the minute we buy cheap products, we are unconsciously increasing our share in air pollution.

“If the cost of imported products is lower because of less stringent air pollution controls in the regions where they are produced, then the consumer savings may come at the expense of lives lost elsewhere,”

This is why their main message is:

“We need to move our lifestyles away from cheap and wasteful,” Qiang Zhang

This research clearly shows the need to measure air quality and act to protect ourselves, regardless of how far we live from the source of pollution. And secondly, makes us understand how our consumption patterns can make a difference in the air quality suffered in other regions of the world.

The Guardian – Thousands of pollution deaths worldwide linked to western consumers
HuffPost – Air Pollution Links People Thousands Of Miles Apart In Deadly Ways
The Economist – Airborne particles cause more than 3m early deaths a year
Nature – Transboundary health impacts of transported global air pollution and international trade

The Air We Breathe and Its Secret Path To The Brain

Previous research had shown a correlation between increased pollution and Alzheimer’s disease; between developing brains exposed to air pollution and mental health; and a link between air pollution and cognitive function in older men. Researchers are increasingly looking at these links and gathering evidence on yet another health effect of the polluted air we are exposed to.

The olfactory system is a direct route for small particles into the brain, especially those small enough to escape through the olfactory bulb. We have recently talked about the link between air pollution and strokes, now a new research from Lancaster University published by the Proceedings of the National Academy of Science has found evidence of toxic nano-particles, which come from air pollution, in human brains and has led to a rich discussion on the possible link between air pollution and Alzheimer’s disease.

In this most recent research, which examined brain tissue from 37 persons from Mexico and Manchester (UK), toxic nano-particles from air pollution -particularly magnetite, have been found in the human brain along with platinum, cobalt and nickel. According to the researchers, the shape and the type of metal indicates that it can only have come from air pollution. Accumulation of metals in the brain is characteristic in Alzheimer’s disease and especially magnetite, which has been previously associated with brain damage in patients with such ailment.

Many scientists have commented on the research results and although it is undisputed that the metal nano-particles in the brain do come from air pollution, many consider that this is not proof that there is a link between air pollution and Alzheimer disease.

Nonetheless, the study explains how the route of these nano-particles into the brain is through the olfactory system. Those particles that are small enough to pass through the olfactory bulb to the brain can lodge in the brain, cortex, hippotalamus and many others almost without barriers. Particles that lodge deep in your lungs can be very damaging because they create inflammation, infection, cancer or go directly to the bloodstream to cause trouble in other parts of the body. However, particles that enter through the olfactory system can be even more damaging because they have direct entrance to the brain where they can damage or kill neurons or even hamper the bains’ immune system.

In fact, both the Alzheimer’s and Parkinsons disease present a loss of the olfactory system capacities very early on. For this reason, many recent studies look at those particles that can be inhaled and have a direct pathway to our brains. One in every 14 persons above 65 suffer from Alzheimer’s diseases.

September is the World Alzheimer’s month, we cannot ascertain that air pollution is linked to Alzheimer, but we can raise awareness on the direct route for nano-particles into our brain.

Protect yourself and your family from air pollution!