The ambient air monitoring station in Sillamäe recorded increases in the concentration of ammonia (NH3) in the air in December, most recently at the end of the month, but the source of pollution has yet to be identified.
Aivar Lainjärv, head of the Ida-Viru County office of the Environmental Inspectorate, told ERR's Russian-language online news portal that, for example, the monitoring station recorded an ammonia concentration in the air of 53.6 micrograms per cubic meter at 8 a.m. on Dec. 26. He noted, however, that this level does not pose a risk to human health.
No air quality limit value has been set for ammonia, however. "According to the earlier Ambient Air Protection Act, [the limit value] was an average over a one-hour period of 200 micrograms per cubic meter," the official noted. "Thus, such a value should still be harmless to one's health."
Lainjärv added that such increases in the concentration of ammonia in the air have previously been recorded in Sillamäe as well, but they unfortunately still have not been able to determine the source or sources of the increase.
"Traces do not remain in the air, and it is unfortunately not possible to constantly monitor all potential sources, but can only prove it through direct measurements," he said.
Between June 15-22 last year, Sillamäe's monitoring station recorded an increase above the norm in the concentration of ammonia in the air, which caused concern among town residents as well.
The Environmental Inspectorate will likely ask the Estonian Environmental Research Centre (KIK) to help determine the source of the ammonia, after which a decision will be made about ordering measurements.
Editor: Aili Vahtla