The monitoring of the nanoparticle concentration

Helsinki region to pioneer a new type of air quality measurement

Helsinki Region Environmental Services Authority (HSY) produces regional and environmental information, performs statutory air quality measurements and participates in active development work in cooperation with universities and product development teams of companies in the field. Pegasor and HSY have been involved in comprehensive national projects that have resulted in sensor and measurement network development as well as the development of real-time air quality modelling and prognosis.

Going beyond statutory requirements

Currently, air quality in the Helsinki region in Finland is monitored on 11 Helsinki Region Environmental Services Authority survey stations. Some of the stations are permanent and others are moved each year. The survey stations monitor the concentrations of several gaseous and particulate pollution air pollutants using many kinds of devices and technologies. In recent years, the monitoring of fine particles has been complemented by research projects through the installation of the Pegasor AQ™ Urban measurement device in ten survey stations. The device produces constantly updating measurement data on the nanoparticle concentration in outside air (LDSA).

“The monitoring of the nanoparticle concentration is voluntary for us, and it is part of our development and research activities. We want to be at the forefront of developing new types of air quality monitoring methods and increasing the utilization of measurements in air pollution control,” says air quality expert Jarkko Niemi from HSY.

Nanoparticles expose the sources of combustion-based local emissions

The new nanoparticle measurement technology provides further information on the monitoring of particle concentrations caused by smoke from small-scale wood burning and traffic emissions. Exhaust fumes from traffic elevate nanoparticle concentrations significantly in environments with heavy traffic, especially during rush hour. The nanoparticle concentration is often elevated in residential areas during winter evenings, when wood is burned in fireplaces and sauna stoves.

Pegasor measurement devices provide information on the sources of local nanoparticle emissions and help us understand them better. Survey stations located in residential areas, in particular, will paint a clearer picture of what kinds of smoke nuisances and emissions local wood burning causes and how different times of day and year affect the readings. At the same time, we can monitor the effects air protection measures and newer vehicles on roads, for example, have on nanoparticle emissions in the long run.

The modern measurement network consists of many technologies

Pegasor measurement devices complement HSY’s modern measurement network and produce accurate, real-time measurement data on nanoparticle concentrations.

“Pegasor’s measuring devices can be used to implement ongoing nanoparticle concentration measurement in the field. Quality monitoring data complements the image of local air quality development and creates prerequisites for academic research into nanoparticles, as data is recorded in the HSY data collection system.”

Long-term measurements provide information on the development of combustion-based fine particles and the effect local air protection measures have on air quality.

Pegasor technology is based on electronic particle measurement, which identifies the lung-deposited surface area concentration (LDSA) of nanoparticles in the range of 10–400 nanometers. Several studies have found it a reliable way of measuring nanoparticles.

High criteria for devices suited to outside air measurements

Affordable, field-ready and reliable measurement equipment are the prerequisite for high-quality, continuous air quality monitoring. Pegasor’s weather-protected measuring device is suitable for long-term outdoor monitoring. The device acts as an independent part of a larger set of measuring equipment. Measurements have been carried out for a few years now in the Helsinki area. Some of the devices are located in HSY air quality survey stations and others operate as independent survey stations in gardens in residential areas, for example.

“We want our measuring devices to be easy to maintain and we want them to produce accurate and stable results. The measurement network out in the field also needs to withstand the elements, especially in the challenging and ever-changing weather conditions in Finland.”

Air quality data to serve residents and urban planning

The air quality data collected by HSY using various technologies serves local residents as well as urban planning. Residents and experts can monitor air quality measurement results in real time on the HSY website and the modelled map service, which also contains an air quality prognosis. The results of nanoparticle measurements are not utilized in the modelled map service as of yet. In the future, real-time information on nanoparticles will be taken into account when drafting air quality prognoses. HSY publishes an annual air quality report, which uses various indicators to assess how air protection work objectives have been met. Results from nanoparticle measurements were published in the 2018 report for the first time.

Air quality data is also utilized in many ways in traffic and urban planning in order to ensure that the urban environment becomes a healthy and beneficial place to live. Street maintenance units, for example, also utilize air quality data. The objective of monitoring air quality is to ensure a healthy, safe and clean living environment. Real-time measurement results and air quality prognoses enable efficient communications concerning air quality. This way, individuals who are sensitive to air pollution, such as asthmatics, could observe air quality better in their everyday choices and prevent exposure to air pollution.