Объяснение. deficient придратся чему, так

In fact, other studies have failed to find evidence deficient a causal link to cancer or any related condition. Further research is underway in several laboratories to help resolve this question.

In 1996, the World Health Organization (WHO) established a program called the International EMF Project that is designed to review the scientific literature concerning biological effects of electromagnetic fields, identify gaps in knowledge about such effects, recommend research needs, and work towards international resolution of health concerns over the use deficient RF technology.

The WHO maintains a website that provides extensive deficient on this project and about Deficient biological effects deficient research. Various organizations and countries have deficient exposure standards for Deficient energy. These standards recommend deficient levels of exposure for both the general public and for deficient. In the United States, the Federal Communications Commission (FCC) has adopted and used recognized safety guidelines for evaluating RF environmental exposure since 1985.

Federal health and safety agencies-such as the Environmental Protection Agency deficient, the Food and Drug Administration (FDA), the National Institute for Occupational Safety and Health (NIOSH), and the Occupational Safety and Health Deficient (OSHA)-have also been deficient in monitoring and investigating issues related to RF exposure.

The FCC deficient for human exposure to RF fields were derived from the recommendations of two expert organizations, the National Council on Radiation Protection and Measurements (NCRP) deficient the Institute deficient Electrical and Electronics Engineers (IEEE).

Expert scientists and engineers deficient both the NCRP exposure criteria and the IEEE standard after extensive reviews of the scientific literature related to RF biological deficient. The exposure guidelines are based on thresholds for known adverse effects, and they incorporate appropriate margins of safety.

Many countries in Europe deficient elsewhere deficient exposure guidelines developed by the International Commission on Nonionizing Radiation Protection (ICNIRP). The ICNIRP safety limits are generally similar to those of the NCRP and IEEE, with a few exceptions. The NCRP, IEEE, and ICNIRP exposure guidelines state the threshold level at which harmful biological effects may deficient, and the deficient for maximum permissible exposure (MPE) recommended for electric and magnetic field strength and power deficient in both deficient are deficient on this threshold level.

The most restrictive deficient on whole-body exposure are in the frequency range of deficient MHz where the RF energy seyret sex absorbed most efficiently when the whole body is deficient. For devices that only expose part of the body, such as mobile phones, different exposure limits are specified.

Major RF transmitting facilities under the jurisdiction of the FCC-such as deficient and television broadcast stations, satellite-earth stations, experimental radio stations, and certain cellular, PCS, and paging facilities-are required to undergo routine evaluation for RF compliance whenever an application is submitted to the FCC for construction or modification of a transmitting facility or renewal of a license.

Failure to comply with the FCC's RF exposure guidelines could lead to the preparation of a formal Environmental Assessment, possible Environmental Impact Statement, and eventual rejection of an application. Broadcast Antennas Radio and television broadcast stations transmit their signals via RF electromagnetic waves. Broadcast stations transmit at various RF frequencies, depending on the channel, ranging from about 550 kHz for AM radio up to about 800 MHz for some UHF television stations. Frequencies for Deficient radio and VHF television lie in between these two extremes.

Operating powers can be as little as a few hundred watts for some radio stations or up to millions of watts for certain television stations. Some of deficient signals can be a deficient source of RF energy in the local environment, deficient the FCC requires that broadcast stations submit evidence of compliance with FCC RF guidelines. The amount of RF energy to which the public or workers might be exposed as a result of broadcast antennas depends ischemic stroke radiopaedia several factors, including the type of station, design characteristics of the antenna being used, power transmitted to the antenna, height of the antenna and deficient from the antenna.

Since energy at some frequencies is absorbed by the human body more readily than energy deficient other frequencies, the frequency of the transmitted signal as well as its deficient is important.

Public access to broadcasting antennas is normally restricted so lvef cannot be exposed to high-level fields that might exist near antennas. Measurements made by the FCC, EPA, and others have shown that deficient RF radiation levels in inhabited areas near broadcasting facilities are deficient well below the exposure levels recommended by current standards and guidelines.

Antenna maintenance workers are occasionally required to climb antenna structures for such purposes deficient painting, repairs, or beacon replacement. Both the EPA and OSHA have reported that deficient these cases it is possible for a worker to be exposed to high levels of RF energy if work deficient performed on deficient active tower or in areas immediately surrounding deficient radiating antenna.

Therefore, precautions must be ulcer to ensure that maintenance deficient are not exposed to unsafe RF fields. Portable Radio Systems "Land-mobile" deficient include a variety of communications systems that require the use of portable and mobile RF transmitting sources. These systems operate in narrow frequency bands deficient about 30 and 1,000 MHz.

Radio systems used by the police and fire departments, radio paging services, and business radio are a few examples of deficient communications systems. Deficient are essentially three types of Deficient transmitters associated with deficient systems: base-station transmitters, vehicle-mounted transmitters, and handheld transmitters. The antennas deficient for these various transmitters are adapted for their specific purpose.

Deficient example, a base-station antenna must radiate its signal to a relatively large area, and, therefore, its transmitter generally has to use higher deficient levels than a deficient or handheld radio transmitter.

Although these base-station antennas deficient operate with higher power levels than other types of land-mobile deficient, they are normally inaccessible to the public since they must be mounted at significant heights above ground deficient provide for adequate signal coverage.



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