PG Spazzini – EMPIR Call 2016 meeting Metrology for Pollution Monitoring Pier Giorgio SPAZZINI INRIM

PG Spazzini – EMPIR Call 2016 meeting Air pollution, despite actions taken in the last decades, is still a growing concern in environmental policies It comes in various flavours: –Particulate pollution (e.g. PM10; presently attention is being focused on lower sizes) –Chemical pollution (e.g. PAHs) –Biological pollution (bacteria etc.) What’s this about?

PG Spazzini – EMPIR Call 2016 meeting Actions can cover a wide range: –immediate (e.g. traffic stops) –Longer term (e.g. more stringent norms) –Planning for the future (e.g vision) What to do?

PG Spazzini – EMPIR Call 2016 meeting And, how? All kind of action, regardless of its span, requires hard and reliable data for: –Decision on action –Decision on level of action –Monitoring of results –Analysis of effectiveness

PG Spazzini – EMPIR Call 2016 meeting So, what do we use? All data about pollution are based on the concepts of concentration, i.e. «how much pollutant (whatever it is) do we have in a given quantity of air»? The quantity of air is expressed as a volume: particles (or micrograms of PAH, or bacteria) per cubic meter

PG Spazzini – EMPIR Call 2016 meeting So, what do we use? Of course, measurements are necessarily made on a statistical basis, i.e. some portion of air will be taken and analyzed and will be considered to be representative of the situation where the measurement was performed Instruments for the measurement of pollutant concentration are known as «air samplers»

PG Spazzini – EMPIR Call 2016 meeting How do we compute concentration?

PG Spazzini – EMPIR Call 2016 meeting How do we compute concentration? The latter equation shows that the (relative) uncertainty on the air volume and the one on the quantity of pollutant have the same influence on the uncertainty on the concentration BOTH quantities will therefore need to be determined with comparable uncertainty in order to have an uncertainty on the concentration of the same order

PG Spazzini – EMPIR Call 2016 meeting How do we compute concentration? In addition, the differences in the flow might also indirectly influence the measurement of the quantity P –Aerodynamic forces on particulates can change if the air velocity changes strongly (change of impact probability –Impact velocity of bacteria can kill part of them if it is too high – and unexpected –Etc.

PG Spazzini – EMPIR Call 2016 meeting What do we need? On the air volume side, we need that our instrument provides an estimate of the flown air with a reasonable uncertainty Instruments presently on the market are not calibrated and often not even verified Their simple construction provides little guarantee regarding the uniformity of measurement in a batch

PG Spazzini – EMPIR Call 2016 meeting What do we need? Also, the influences on the measurement of ambient conditions are poorly known In conclusion, an assessment and improvement of the measurement of air quantity aimed at air pollution monitoring would lead to an improvement of the environmental policies