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Description of the indicated harmful variables for the human organism and their elimination in living
spaces:
The values are indicative only. Each individual reacts differently to different substances, and what
may be harmless to one may cause trouble to another. If you are concerned about your health, we
recommend that you discuss the issue with an expert. If you are unable to reduce the levels of the indicated
variables in your home to the desired values, we recommend discussing the problem with an expert.
These limits are indicative only. You may use the lower "alert" limits, which will not hurt you in any
way. If you seek less indoor ventilation in winter, for example, you can temporarily tolerate exceeding these
alerts. In the factory settings, the limits are set to alert you to exceeding those limits where it is generally
agreed that such levels may be hazardous to health (based on international health and medical
recommendations).
Radon concentration Rn, radon volume activity (RVA)
–
Radon is a natural, colourless, tasteless
and odourless gas produced by the radioactive decay of radium, thorium and uranium in rocks and released
in varying amounts from the Earth's crust. Radon gas enters the atmosphere from the ground surface or
enters directly into buildings from the subsoil that do not have radon insulation or that have poor quality
insulation (e.g., poorly sealed utility penetrations). Another source of radon in buildings include poor quality
building materials or local water sources. Inadequate ventilation of buildings can lead to radon retention in
the building and excessive radon accumulation inside. Prolonged exposure to high concentrations of radon
can cause lung cancer (radon is the second most common cause of lung cancer).
Excessive levels can be reduced by ventilating the space. Due to the method of measurement
(moving average of the values over 6 hours), the effects of ventilation will be slightly delayed. The reference
value is considered to be 300 Bq/m
3
(annual average). Under the (Czech) law, publicly used premises
(schools, gyms) and workplaces should not exceed this value on average for the whole year. In households,
we would also recommend not to exceed this value, or try to keep it as low as possible, especially if children
stay in the area for a prolonged time. For more information about radon and how to protect yourself from
it, visit
https://www.radonovyprogram.cz/
Ideally, we would recommend having the RVA at home of 200 Bq/m
3
(at times when persons stay
inside), but in some older buildings this may be challenging without structural modifications.
Equivalent dose power from photon radiation (X-ray and gamma radiation) –
X-ray and gamma
radiation is high-energy electromagnetic radiation produced by radioactive and other nuclear decay capable
of ionizing matter (ionizing radiation). When living organisms are overexposed to ionising radiation, they
can be damaged. Short-term exposure to intense ionizing radiation can cause radiation burns or various
stages of acute radiation sickness. Lifetime accumulation of minor damage from ionizing radiation can
induce various types of cancer.
Long-term above-limit values may indicate a nuclear accident or the presence of a source of
ionising radiation in the room (a piece of uranium ore, uranium glass, hazardous building material). The
legal limit for the general population is 1 mSv/year from artificial radiation sources (not including natural
and medical radiation). The natural radiation in Czech geological conditions can range from 0.04 to 0.32
µSv/h. Values greater than 0.5 µSv/h are already suspicious; values greater than 1 µSv/h should not be
present in homes and this should be investigated. The equivalent dose is strongly dependent on the
distance from the radiation source (if you put the source close to the product, it may show high values). In
the event of long-term overexposure, inform the relevant authorities. Further reading on the website
https://www.suro.cz/cz/faq/jake-hodnoty-davkoveho-prikonu-muzeme-v-cr-ocekavat
As the maximum acceptable value at home, we would recommend a value of 0.5 – 1.0 µSv/h
(depending on the natural background in your area).
Carbon monoxide concentration CO
– Carbon monoxide is a colourless, tasteless and odourless
poisonous gas that does not irritate the senses. In households, it can mainly arise as a product of imperfect
gaseous, petrol or fossil combustion from heat sources.
Levels above 100 ppm are hazardous to health (in case of prolonged exposure) and persons should
not stay in such areas. However, levels at 35 ppm may already cause certain side-effects in some people,
while at values above 50 ppm these side-effects occur in almost everyone (especially headaches in case of
prolonged exposure). At concentrations above 150 ppm, death can occur in case of prolonged exposure.
