J. Inst. Pub. Hlth. Engr. India,: 56-62, 1993.
D. B. BORALKAR
Central Pollution Control Board, 'Parivesh Bhawan', C.B.D.-cum-Office Complex, East Arjun Nagar, Delhi-110 032.
Table 2 : Classification of air pollutants in Norway
| Compound | Effect on | Averaging time | Classification criterion |
|---|---|---|---|
| SO2 | Health, materials and vegetation | 1 day | 100 ug/m3 |
| 6 months | 30 ug/m3 | ||
| Seat | Health | 1 day | 100 ug/m3 (high limit) |
| 6 months | 40 ug/m3 (high limit) | ||
| 6 months | 20 ug/m3 (high limit) | ||
| NO2 | Health | 1 hour | 200 ug/m3 |
| 1 day | 100 ug/m3 | ||
| 6 months | 75 ug/m3 | ||
| CO | Health | 1 hour | 25 mg/m3 |
| 8 hours | 10 mg/m3 | ||
| O3 | Health and vegetation | 1 hour | 120 ug/m3 |
| F | Vegetation and animals | 1 day | 1.0 ug/m3 (gaseous F) |
| 1 month | 0.2 ug/m3 (total F) | ||
| 6 months | 0.3 ug/m3 (gaseous F) | ||
| Dustfall | Welfare | 1 month | 5 g/m2 |
| S | Acidification | 1 year | 0.5 g/m2 |
Monitoring of concentrations and effects of different air pollutants is necessary for prevention and control of air pollution. Without data on concentrations and effects, there is no possibility of studying the occurrance and distribution of air pollutants and their effects in place and time, of setting standards for the protection of man and his environment, and of checking the results of abatement measures. What we need is an alarm system in order to prevent the occurance of excessive concentrations, resulting in hazardous effects on man, other animals, plants and materials. For these purposes both physical/chemical concentration measurements along with biological effect measurements with plants are needed.
The concentrations measured by physico-chemical methods are not sufficient to predict all possible effects of air pollutants, and indicator plants will never be able to give information about identity and concentration of all polluting agents in air. There is no question of replacing ambient air monitoring by physical/chemical methods with effect-monitoring with plants; both should be used jointly. Ambient concentration measurements, effect intensity measurements on plants (including chemical/physical leaf analysis), and measurements of meteorological parameters may together produce the total picture of the pollution situation (Posthumus, 1984).
The work discussed earlier proves that plants can be used for the purpose of air monitoring as a cheap instrument and technique is easy for adoption. The biological-effect monitoring network regularly spread all over the country can be set up in close co-operation with other air quality monitoring network. The sensitive indicator and/or accumulator plants could be used in a standardised way. The need for the formulation of a national programme on the use of bioindicators for air quality is, therefore, strongly felt.