Table 4.
Comparison of reduction percentage in PM with different studies.
| Study | Year | Region | Source | Type of Filter | Reduction in PM Level |
|---|---|---|---|---|---|
| Batterman et al. | 2005 | Michigan | Cigarette Smoke | HEPA | 30–70% |
| Myatt et al. | 2008 | US | Environmental Tobacco Smoke | HEPA | 70–80% |
| Du et al. | 2011 | Michigan | General indoor air | HEPA | 69–80% |
| Batterman et al. | 2012 | Michigan | General indoor air | HEPA | 50% |
| Present Study | 2018 | India | Candles and incense | HEPA(AP I) HEPA(AP II) | 29–53% 52–68% |
| General indoor air | HEPA (AP I) HEPA(AP II) | 12–52% 37–64% |