How indoor air can be purified naturally

Today morning I got a message from an artist-cum-businessman friend of mine. He was actually trying to sell me an air purifier!

With the pollution levels rising day by day, I am pretty sure more and more people want to buy this machine my friend was trying to sell. And it comes with a warning that air pollution can actually kill you soon and an assurance that this machine can become your saviour. A marketing strategy that can block your free will and make its slave!

Well, but I am not going to surrender my free will to this marketing gimmick. Because I know how to purify air in the natural way! And I am going to tell you too this 'secret'.

Indoor air pollution is not a new phenomenon. Since the dawn of history, humans have burnt wood, peat or coal to produce heat. The walls of caves, inhabited millennia ago, are covered with layers of soot and mummified bodies from the stone ages often have blackened lungs. 

A typical modern home has lots of different sources of pollution: heating, cooking, cleaning, smoking, perfumes and furnishings. Even the simple act of moving about stirs up particles. Demands to improve the energy efficiency of buildings comes with the concern that more airtight homes could have an adverse effect on indoor air quality. 

The air inside your home may already contain all sorts of unwanted stuff such as particulate (microscopic bits of solid or liquid matter), carbon monoxide, oxides of nitrogen, formaldehyde, radon, and volatile chemicals from fragrances used in conventional cleaners. Then there are the “bioaerosols” – bacteria, fungi, viruses, house dust mites and bits of skin shed by furry or feathered animals. 

Sick building syndrome (SBS) is used to describe situations in which building occupants experience acute health and comfort effects that appear to be linked to time spent in a building, but no specific illness or cause can be identified. A 1984 WHO report suggested up to 30% of new and remodeled buildings worldwide may be subject of complaints related to poor indoor air quality.

Sick building causes are frequently pinned down to flaws in the heating, ventilation and air-conditioning (HVAC) systems. Other causes have been attributed to contaminants produced by outgassing of some types of building materials, volatile chemical compounds, moulds,  improper exhaust ventilation of ozone (byproduct of some office machinery), light industrial chemicals used within, or lack of adequate fresh-air intake/air filtration.

First of all let me also tell you how not to pollute your house with toxic fumes and other unwanted substances.

1. If you are living in a highly polluted busy street, close all the doors during busy traffic hours of the day and open them during early hours when pollution is less. If you are living in less polluted areas open the windows to increase the ventilation. If you’re cooking it is important to use the smoke chimney otherwise levels of nitrogen dioxide can exceed those on the most polluted roads.

2. If you can try to install water fountains outside of your house that can absorb toxic gases and prevent them from entering your place.

3. Plant lots of trees around your house that can become a wall of protection.

4. When you are painting your house or inside your house (creating artworks)  keep all the doors and windows open as long as possible for the toxic fumes to disperse. Use fans to quicken the process.

5. Reduce or if possible avoid using plastic and synthetic materials in the house. Try to use natural products. For example, use cotton beds instead of foam ones. At least keep them out for a few days immediately after buying them until they reduce emitting toxic fumes. Plywood, kitchen cabinets made of artificial materials and insulation material contain harmful chemicals. It is better to use natural wood. Don't use PVC pipes and floor coverings that contain toxic chemicals. Use iron pipes and carpets made of natural products.

6. Room and bathroom fresheners contain allergic chemicals, stop using them. Instead you can use natural flowers and sandalwood. Choose personal beauty care products that are fragrant free. Use of hair sprays and deodorants inside the house should be stopped. Polish your nails outside of your house, i.e., in the balconies or gardens. Use polish removers too outside. 

7. Keep the house clean, dry and moist-free as far as possible. Ensure proper ventilation in damp areas, such as bathrooms. This will stop Fungus from growing. 

8. Check all the systems working in the house for proper working conditions, leakages etc.

9. Don't use smoke-emitting cooking surfaces/devices or fume-emitting oils, agarbatti/incense-sticks in the house.

10. See that proper ventilation systems are installed in the house.

11. Never allow anybody to smoke in your house.

12. When you light a candle /match stick/lighter or use any sort  of fire in your home, always open the windows and doors. 

13. Choose hard-surface floors. They’re easy to clean. Carpets can let dirt and pet hair escape back into the air. 

14. Use a doormat to prevent dirt from entering into your home.  Remove and leave your shoes at the entrance of your home and ask people to take off their shoes when they visit you. 

15. Household cleaners, paints, solvents should not be stored at home. Disinfectants, synthetic pesticides  should not be sprayed inside the house as far as possible. 

If you still find breathless in your home/work place after following all the above instructions, you can use the following in-door plants to naturally purify the air in your living/working place.

While some houseplants specialize in targeting one type of pollutant or another, others generalize and attack the total problem head-on. Several common houseplants familiar to indoor gardeners do well in removing a broad spectrum of pollutants. 

Fire wall against pollution - my art installation ( www.kkartfromscience.com )

Trees and plants too are known to improve air quality by capturing six common air pollutants and toxic gases: ground-level ozone, particulate matter, carbon monoxide, nitrogen oxides, sulfur dioxide and lead. In fact, a single tree can absorb 10 pounds of air pollutants per year. The greater the tree cover, the greater the pollution removal, and the greater the removal and population density, the greater the value of human health benefits. Numerous recent studies have focused on the positive effects that exposure to trees and nature has on our mental health.

Even a single houseplant can make a difference in your home's indoor air quality. Just one efficient 6- to 8-inch-diameter plant can clean the air of a 10-feet-square room. By varying the size and locations of your houseplants, you can affect air quality throughout your home. Optimize the effect of these natural air purifiers through these considerations:

• Placement: Proximity matters. The area closest to cleansing plants will be most affected, so place these natural purifiers throughout your home accordingly.
• Plant health: Plants operate at top levels of air-cleansing efficiency when they're at peak health. Follow best practices for indoor plant care, and make the most of your greenery. Well-aerated roots are especially important to cleaning air, so avoid over-watering.
• Plant size: Air cleansing occurs through natural process that happen in plant leaves and roots. The larger the leaf surface and root system, the greater the impact on air pollutants. 

By adding air-cleaning houseplants to your home, you can bring the garden indoors and make your home a cleaner, healthier place as well. Living plants can add indoor beauty and circumvent cares about clean air

This list has been provided by NASA. The NASA Clean Air Study has been led by the National Aeronautics and Space Administration in association with the Associated Landscape Contractors of America (ALCA). Its results suggest that certain common indoor plants may provide a natural way of removing toxic agents such as benzene, formaldehyde and trichloroethylene from the air, helping neutralize the effects of sick building syndrome.

But first caution to be observed...

Plants do emit CO2 during night , like we do 24x7. If you have too many of them in a closed room, you will start competing with them for the Oxygen. So be careful.
You need to pick plants, which should be chosen by observing cultural wisdom around different societies.
Some plants can be toxic, hence do not use them if you have some naughty kids and pets. Always consider personal sensitivities and the potential for toxicity when choosing houseplants for your home.

Although several well-known studies have found that houseplants are effective at purifying indoor air, some studies point out that the soil and pots in which they grow, along with the pesticides used to treat them, contain harmful microorganisms that can potentially contaminate indoor air.

If you're planning to utilize houseplants as part of a comprehensive plan to improve respiratory health, NASA suggests using 1 house plant for every 100 square feet of space.

In order to effectively remove VOC's from the air in your home, houseplants should be kept in energy-efficient, non-ventilated buildings. 

Before investing in houseplants, make sure you know how to properly care for them and that your doctor is aware of how you plan to use them.

Some houseplants can be toxic to animals. Before you buy one, talk to your local Gardening Store or Nursery to see which ones are safest for indoor use.

You can try these plants:

Fist choice should go to Areca plant - Dypsis lutescens, these are beautiful and typically non toxic. These are also called Butterfly plants

Next choice should be any variety of Money plant - Epipremnum aureum, This grows like a creeper, hence you can choose if you have enough place and some hooks around the room.

If you are OK with the texture of a snake, then go for Snake plant -

Sansevieria trifasciata

It consumes less Oxygen during night and continues to emit some Oxygen back even in low light.

Chart of air-filtering plants

( Source: NASA_Clean_Air_Study )

Plant, removes:	benzene[2]	formaldehyde[2][5]	trichloroethylene[2]	xylene and toluene[6]	ammonia[6]
Dwarf date palm (Phoenix roebelenii)	no	Yes[5]	no	Yes	no
Areca palm (Dypsis lutescens)	no	no	no	Yes	no
Boston fern (Nephrolepis exaltata 'Bostoniensis')	no	Yes[5]	no	Yes	no
Kimberly queen fern (Nephrolepis obliterata)	no	Yes[5]	no	Yes	no
English ivy (Hedera helix)	Yes	Yes[5]	Yes	Yes	no
Lilyturf (Liriope spicata)	no	Yes	no	Yes	Yes
Spider plant (Chlorophytum comosum)	no	Yes[2]	no	Yes	no
Devil's ivy, Money plant (Epipremnum aureum)	Yes	Yes[2]	no	Yes	no
Peace lily (Spathiphyllum 'Mauna Loa')	Yes	Yes[5]	Yes	Yes	Yes
Flamingo lily (Anthurium andraeanum)	no	Yes	no	Yes	Yes
Chinese evergreen (Aglaonema modestum)	Yes[5][8]	Yes[5][8]	no	no	no
Bamboo palm (Chamaedorea seifrizii)	no	Yes[2][5]	no	Yes	no
Broadleaf lady palm (Rhapis excelsa)	no	Yes	no	Yes	Yes
Variegated snake plant, mother-in-law's tongue (Sansevieria trifasciata 'Laurentii')	Yes[5]	Yes[2]	Yes[5]	Yes	no
Heartleaf philodendron (Philodendron cordatum)	no	Yes[2]	no	no	no
Selloum philodendron (Philodendron bipinnatifidum)	no	Yes[2]	no	no	no
Elephant ear philodendron (Philodendron domesticum)	no	Yes[2]	no	no	no
Red-edged dracaena (Dracaena marginata)	Yes	Yes[2]	Yes	Yes	no
Cornstalk dracaena (Dracaena fragrans 'Massangeana')	Yes	Yes[2]	Yes	no	no
Weeping fig (Ficus benjamina)[9]	no	Yes[5]	no	Yes	no
Barberton daisy (Gerbera jamesonii)	Yes	Yes[5]	Yes	no	no
Florist's chrysanthemum (Chrysanthemum morifolium)	Yes	Yes[2][5]	Yes	Yes	Yes
Rubber plant (Ficus elastica)	no	Yes[5]	no	no	no
Dendrobium orchids (Dendrobium spp.)	no	no	no	Yes	no
Dumb canes (Dieffenbachia spp.)	no	no	no	Yes	no
King of hearts (Homalomena wallisii)	no	no	no	Yes	no
Moth orchids (Phalaenopsis spp.)	no	no	no	Yes	no

However, new research finds that you would need between 10 and 1000 plants per meter squared to gain any real air quality benefits.

Researchers analyzed 196 experiments from 12 previously published studies and concluded that indoor houseplants don’t actually improve air quality enough to make a difference in the amount of volatile organic compounds polluting indoor air.

Volatile organic compounds, or VOCs, are a class of chemicals that can be “off-gassed,” or emitted as gases, and negatively impact our health. VOCs are found in household products such as paints, cleaners, disinfectants, and air fresheners, as well as office equipment like printers, glues, and permanent markers. Some examples of specific VOCs are formaldehyde (used in resins in some wood or building materials), methylene chloride (a component in paint strippers or adhesive removers), and benzene (found in tobacco smoke). While trace amounts of these chemicals can be found in the air outdoors, a study that measured the amount of VOCs indoors found levels of these pollutants between two and five times higher than in the air indoors.

In 1989, a report on using plants for mitigating indoor air pollution was published by Bill Wolverton, an indoor air quality researcher, as part of the NASA Clean Air Study. The study aimed to find ways to purify the air inside space stations. The researchers placed 12 different plant species in sealed chambers: these included ficus, peace lily, mother-in-law’s tongue, and others. They tested three types of VOCs (formaldehyde, benzene, and trichloroethylene) by adding them to the chamber with each plant species and recording how much of the gas was left after 24 hours. Wolverton reported that across all of the trials, between 10-70 percent of the added VOCs were removed. Wolverton’s report has since become a model for other research to follow, and some plant stores even reference it in their advertising.

But Cummings and Waring, in their recent study, pointed out that the results from these studies can’t realistically translate to their impacts on actual indoor spaces. The plants in previous studies were grown in very small chambers. How small? Typically, around a cubic meter in volume, or about the space a large armchair takes up. That doesn’t reflect the sizes of the rooms we typically spend our time in. Also, most of the studies introduced VOCs into these small chambers and then sealed them up so the gas could not escape. While that allowed for conveniently controlled experiments, they contrast with the typical indoor spaces that are constantly bombarded in flux as people and pets walk in and out and air flows from the outside, through the room, and back out again. Rooms are just not the same as tiny, sealed chambers.

To address this, Cummings and Waring wanted to re-examine previous studies to better predict the effectiveness of houseplants for purifying air. But they had an added challenge in that all of the previous studies used different metrics to report their results. To accurately compare the results, they developed a standardized metric called clean air delivery rate (CADR) for the plants from each experiment. By digging into the setup of each of these studies, they could calculate a CADR value that reflected the amount of air pollutants that a given plant could remove from a given space (a cubic meter) each hour. Once they compiled the results and accounted for larger spaces, even the best CADR value from the plants was less than 1 percent of the capacity of an air purifier.

This is a lot of plants, but this new study suggests that it would take many times this number to make a dent in indoor air quality

So, houseplants seem to be able to remove VOCs. But not very much – you’d have to somehow stuff between 10 and 1000 plants per meter squared in a room for them to even be comparable to air exchange from indoor-outdoor air flow.

This might sound disappointing, but houseplants aren’t just taking up money and space and doing nothing either. While this study shows that houseplants might not play a role in removing VOCs to improve indoor air quality, other studies have shown that houseplants can alter the indoor microbiome, increasing microbial abundance and diversity and potentially preventing harmful bacteria from settling in. This is among the many other documented studies of how houseplants can improve our productivity by increasing workplace satisfaction and mental wellness by lowering stress and anxiety. To all the houseplant-doting #plantparents out there, that’s probably still quite worthwhile.

https://massivesci.com/articles/houseplants-air-pollution-quality-v...