A portable measurement unit to monitor the air we breathe
Mäkelä, lecturer at Tampere University of Technology (Left)
and Jarmo Lilja, lecturer at TAMK University of Applied Sciences
scrutinising the results of measurements of fine particles from the
outside air in the city of Tampere.
High resolution image (340 Kb)
Photo: Kalle Heiska
we breathe coarse particles (diameter 2.5 to 10 micrometers) and larger
fine particles (all under 2.5 micrometers) immediately irritate the
respiratory tract, stick in people’s bronchi and exit the body a
few hours later when they sneeze or expel mucous. Typical examples are
dust from streets and roads and, for example, airborne salt particles
resulting from waves crashing against the coast.
Smaller fine and extra fine particles penetrate deep into the body through the saccules in the lungs and enter the veins and heart. Their contribution to sickness has only recently been researched; for example, in the USA an association has been demonstrated between hospital visits due to heart and circulatory symptoms and the microparticle counts in the area. Changes in the coarse particle count were not associated with the occurrence of such symptoms.
The EU has set a target value for outdoor air in 2010 regarding the maximum total mass of particles under 2.5 micrometers at an average of 25 microgrammes per cubic metre per 24 hours. In 2015 that target value will become a limit for official action.
The measuring device in the TAMK mobile instrument was used on instructions from the city administration to investigate the quality of air in the Kaleva area of the city. These findings are currently being compared with those of a fixed measuring station in another part of the city. The aim is to compare the findings of measurements of fine particles against the statistics of local hospitals and health centres on respiratory and heart symptoms. It is estimated that in Finland there are some 200 – 1,300 premature deaths due to extra fine and the very finest particles in the air.
ELPI, or Electrical Low Pressure Impactor, the TAMK portable unit is capable of measuring particles with diameters from 7 nanometers to 10 micrometers. The device in the portable unit separates the mass accumulation of the different sized particles and the number of particles. International health and physics researchers are increasingly interested in finding out more about a possible association between particles under 0.5 micrometers in diameter and cardiovascular diseases. Among the most recent research objects is a possible dependency of increasing importance on the total surface area of these particles. This is one of the interesting quantities the measuring instrument developed by Dekati is already able to measure.
The portable measuring instrument is part of the TAMK research and development work and six theses were accomplished in the course of its construction. The vehicle also includes devices for measuring oxidants, air temperature and humidity and wind characteristics. Towed behind a private car, it can easily be taken wherever it is needed.
|TAMK University of Applied Sciences
Lecturer, Dr. Tech. Jarmo Lilja
Tel. +358 50 554 2440
|City of Tampere
Environmental inspector Milla Hilli-Lukkarinen
Tel. +358 3 5656 6656
|Tampere University of Technology
Lecturer, Docent Jyrki M. Mäkelä
Tel. +358 40 733 5405