After becoming allergic to New Delhi's polluted air in 1992, Meattle claimed to have discovered that three common houseplants could help reduce the pollutants in the air.[2] The three plants and their properties are listed below:
- Works well in the day time
- Great for living areas
- One needs about 4 shoulder-high plants/person
- Needs to be put outdoors once every 3–4 months
- The leaves of the plant need to be wiped every day in Delhi and perhaps once a week in a cleaner city
- The soil used should be of vermi manure or use hydroponics
- Converts CO2 into O2 at night
- One requires about 6–8 such waist-high plants per person in the bedroom
- Leaves need to be wiped in the same way as the Areca Palm
- The soil used should be of vermi manure or use hydroponics
Meattle does not provide any numerical data to support his claims,[3] nor is there third-party confirmation of the results, but at least one study calls the hypothesis into question.[4]