1. What rules are to be observed when operating baby monitors?
These are
the answers by BfS
1. What rules are to be observed when operating baby monitors?
Baby monitors – sometimes called Babyphone, Baby Talk or Baby Watch, depending on manufacturers and registered trademarks – transmit sounds from the baby’s room to any other room so that parents can check on their sleeping baby or toddler from distance. Most types of devices used today transmit acoustic
signals by radio link via high frequency electromagnetic fields. The
transmitter power is generally low because of the baby monitor’s rather short range. For reasons of precaution, however, BfS recommends to use devices labelled with the “Blue Angel”.
Apart from high frequency electromagnetic fields,
mains-operated baby monitors also create electric and magnetic fields with
frequencies around 50 Hz. The intensities of these low frequency fields
decrease rapidly with distance to the device. However, since baby monitors
produce a long-term field exposure, BfS recommends, for reasons of precaution,
to keep the distance to the baby’s bed as far as practicable without disturbing
the functioning of the baby monitor. If possible, the device should be operated
on batteries so that no alternating low frequency fields are created in the
first place.
Since the end of 2006, the ecolabel "Blauer Engel" provides guidance to parents wishing to buy baby monitors which emit as little radiation as possible for reasons of precaution. The ecolabel does not only consider criteria relating to high frequency and low frequency fields but also sets requirements for energy consumption and the materials used by the manufacturer.
2. Are there any risks associated with ‘satellite dishes’?
Parabolic antennas (so-called ‘satellite dishes’) receive TV and radio transmissions which are emitted by satellites. They only receive
signals and do not emit high frequency radiation themselves. Therefore, the use
of satellite dishes does not involve any health risks due to high frequency electromagnetic fields.
3. Is the use of radar radiation for road traffic controls
danerous?
Traffic radar equipment commonly used for speed control in
road traffic is operated at very low transmission power < 1.5 W EIRP. The electromagnetic
fields are transmitted straight forward and at a very short distance from the measuring device (a few metres) already ensures that the electromagnetic fields are reduced to a fraction of the limit values. Therefore such equipment does not represent a relevant health risk due to high frequency electromagnetic fields, neither to the operators of the measuring devices nor to the public.
4. Is radar radiation used at airports dangerous?
Radar systems are used at airports to control the air
traffic. These systems operate at gigahertz frequencies. Radar systems at
airports also require a site approval of the German Federal Network Agency
(Bundesnetzagentur) according to the “Ordinance on the method of proof
regarding the limitation of electromagnetic fields” (BEMFV). This will only be
granted if limit values of the 26th Ordinance on the Implementation of the
Federal Emission Protection Law (Ordinance on electromagnetic fields – 26th BImSchV) are complied with in public areas. According to current scientific knowledge high frequency fields of radar systems do not involve any health risks to the general public if limit values are observed.
5. Have health effects from electronic article surveillance devices been observed?
Electronic article surveillance systems, which are
used in department stores and supermarkets and increasingly in public services, e.g. libraries, are supposed to prevent goods from being stolen. A hard tag or an adhesive label, depending on the type of good, is attached to products to ensure protection. If these tags or labels are not deactivated before they are passed through the detectors, they set off an alarm.
A great number of different systems is currently in
operation. Either low frequency magnetic fields or high frequency
electromagnetic fields are used to detect the tags or labels with the help of
continuous signals or different types of pulses.
The field intensities can reach relatively high pulse peaks
between the detectors but outside the surveillance area the field intensities
decrease rapidly with increasing distance.
As a rule, electronic article surveillance systems do not
involve any health risks to the general public, since the exposure time is
generally quite short. For reasons of precaution, however, one should not
remain between the detectors any longer than absolutely necessary.
This applies in particular to people wearing active and
passive body aids (such as pacemakers, infusion pumps or metallic implants),
since health effects cannot be excluded in these cases. If you belong to this
group of people, please make sure that you pass through detectors as quickly as
possible and do not remain between detectors while queuing at the cash desk.
For further information on any health risk associated with electronic article surveillance systems please ask your attending physician.
6. Are microwave ovens dangerous for the user?
Microwave ovens use high frequency radiation at gigahertz
frequencies (2.45 GHz) in order to heat food rapidly. The cooking chamber is shielded
to ensure that only a very low amount of microwave radiation can leak to the
outside. As a further safety measure every oven has to have several independent
protective interlock systems that stop the production of microwaves the very moment
the door is opened.
There is no reason to fear adverse health effects from
leakage radiation. BfS has conducted comprehensive and representative
measurements on microwave ovens. Leakage radiation was observed around the
screens and doors of all microwave ovens, but only at extremely low levels. At
places around microwave ovens where users usually operate detectable radiation
was more than a thousand times below the legal limit. Intact devices thus do
not represent a health risk to the user.
According to current knowledge, exposure to microwaves does
not provoke any harmful changes in food quality either. Both the nutritional
value and the hygienic quality of heated food depend in particular on the
user’s reasonable behaviour. So please make sure to follow the manufacturer’s
instructions carefully if you intend to heat food in a microwave oven.
7. How do radio amateurs ensure that their equipment
complies with the legal limits?
The frequency spectrum that is used with amateur radio
equipment ranges from medium waves to microwaves. Certain frequency bands
within this spectrum are allocated for amateur radio.
In Germany, amateur radio stations are not regarded as
commercial transmitters. Radio amateurs are only allowed to operate
transmitters if they have passed a special training to prove their
qualification and if they hold a personal licence. Such a licence includes the
personal responsibility not to impair the neighbourhood.
Since the Amateur Radio Service is an experimental radio
service by nature, the users’ equipment and antennae are subject to frequent
changes. According to the German Amateur Radio Service Act (AFuG) radio
amateurs themselves shall guarantee compliance with the legal limits for the
general public in publicly accessible areas. They must be able to carry out the
required measurements and calculations in order to prove compliance with the
relevant regulatory standards.
The “Ordinance on the method of proof regarding the
limitation of electromagnetic fields” (BEMFV) of August 20, 2002 requires a
site approval for stationary amateur radio equipment if the conditions set out
in §§ 8 ff. BEMFV are fulfilled. This is the case, according to
§ 8, section 1 BEMFV, if any stationary transmitters (e.g. for mobile communication) which are
subject to the regulations regarding site approval set out in § 4 BEMFV
are already operated at the site envisaged. In the event that the total
radiated power (EIRP) at the site envisaged amounts to or exceeds
10 watts, a stationary amateur radio transmitter shall only be operated on
the following conditions:
- The site-specific safety distance lies within the
controllable area;
- the operator has reported to the authorities according to
§ 9; that the operational data do not exceed the data indicated in such
notice or application,
- the transmitter does not cause any adverse health effects to
individuals, in particular to people wearing active body aids.
The German Federal Network Agency (Bundesnetzagentur) is
allowed to revoke the licence to participate in the Amateur Radio Service if
the radio amateur persistently violates the Amateur Radio Service Act or other
rules and regulations (§3, section 4, AFuG).
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