LCQ6: Radiofrequency electromagnetic fields of mobile phones

     Following is a question by the Hon Chan Kin-por and a reply by the Acting Secretary for Food and Health, Professor Gabriel Leung, in the Legislative Council today (July 13):


     The World Health Organisation (WHO) of the United Nations has recently classified mobile phones as possibly carcinogenic to humans, and placed them in the same category as pesticides, human immunodeficiency virus and plasticiser which has attracted wide media coverage recently.  WHO has advised that prolonged use of mobile phones is associated with the risk for acoustic neuroma, and that using mobile phones for more than 30 minutes daily will result in an increase in the risk for gliomas by 40%.  Medical specialists have pointed out that a malignant glioma cannot be completely cured, and only half of the patients with such a tumour have a survival rate of one year.  In this connection, will the Government inform this Council:

(a) whether the authorities will follow up the WHO report by conducting a study on the effect of exposure to radiation from mobile phones on public health; if they will, of the details; if not, the reasons for that; given that it has been pointed out in the Lancet, an international medical journal, that the amount of radiation absorbed by the head tissues of children is two times higher than that of adults, and the Department of Health has also advised that children should avoid using mobile phones frequently, whether the authorities will specifically warn parents of young children about this and encourage members of the public to use hands-free devices as far as possible or even use communication means which can reduce exposure to radiation such as SMS messages;

(b) given that the Office of the Telecommunications Authority (OFTA) currently encourages mobile phone manufacturers, suppliers and dealers to affix labels on a voluntary basis to mobile phones stating that they are type-approved, yet these labels do not show the Specific Absorption Rate (SAR) of mobile phones, which is a measure of the amount of radiofrequency radiation absorbed by the organs of a person when he is using a mobile phone, and that among the mobile phones which are confirmed to have complied with OFTA's standard on the safety limits of radiofrequency radiation at present, the difference in their SARs can be over 27 times, whether it knows if OFTA will consider requiring mobile phone manufacturers, suppliers and dealers to affix labels to the packaging boxes of mobile-phone products to state the products' radiation data for public reference; and

(c) as OFTA is applying two different standards on the safety limits of radiofrequency radiation for mobile phones, whether it knows if OFTA has any plan to apply the most stringent standard only; given that the information provided by the National Cancer Institute in the United States shows that mobile phones will have higher radiation emission level in poor reception areas, and OFTA has also advised that members of the public should consider avoiding using mobile phones in poor reception areas, whether the authorities will check the strength of signals of mobile phone networks in individual areas, in particular remote areas, and further assist mobile network operators in improving the coverage of mobile networks in poor reception areas, so as to obviate the need for mobile phones to increase the radiant power over a prolonged period in order to search and maintain signals, which will affect public health?


Acting Madam President,

     On May 31 this year, the International Agency for Research on Cancer (IARC) under the World Health Organisation published its assessment on the carcinogenicity of radiofrequency electromagnetic fields, giving rise to concerns among some members of the public.

     Unlike ionising radiation such as X-rays and nuclear radiation, radiofrequency electromagnetic fields generated by mobile phone technology are a type of non-ionising radiation.  Simply put, non-ionising radiation has lower energy and is insufficient to change the chemical properties of substances.  It cannot cause harm by breaking chemical bonds in the human body.

     Radiofrequency electromagnetic fields may generate a small amount of heat when absorbed into the human body.  This would normally not give rise to any adverse health effects as the human body's normal thermoregulatory processes can carry this heat away.

     In 2000, IARC launched an international study named Interphone to research into whether there was any association between mobile phone use and brain tumours.  To date, this has been the largest study of its kind.  In 2010, the Interphone study concluded in its report that -

(i) There was no data indicating an increased risk of glioma and meningioma amongst people who had used mobile phones for over 10 years;

(ii) There was no consistent trend that showed risk increasing with longer mobile phone call times; and

(iii) Although statistically, the 10% of the sampled population with the highest cumulative call time (i.e. accumulating over 1 640 hours of calls over the 10 years, or averaging over 30 minutes of calls per day) had a higher risk of glioma, there were limitations in the study method that could lead to bias and error in the data.  The results are certainly not equivalent to an increased risk of glioma upon making mobile phone calls for over 30 minutes per day.

     In sum, the Interphone study did not come up with any strong or valid conclusion, nor did it explain any causal relationships.  In fact, there are numerous risk factors which may cause cancer.  IARC suggests that more extensive research is required in order to eliminate all other factors in ascertaining whether the use of mobile phones in itself is carcinogenic.

     Nevertheless, on the basis of the above data, IARC classified radiofrequency electromagnetic fields as a Group 2B cancer-causing agent on May 31 this year.  By definition, Group 2B agents are "possibly carcinogenic to humans".  Generally speaking, there is less than sufficient evidence in experimental animals and only limited evidence in humans showing that agents classified under Group 2B are carcinogenic.  As a matter of fact, many agents found in our daily lives are also classified as Group 2B agents, such as coffee and certain dry cleaning agents.  The proven health risk is far lower than that of asbestos, smoking, second-hand smoking, nicotine and ionising radiation, etc.

     While there is no evidence showing that mobile phone use would increase the risk of brain tumours, a large amount of research is under way around the world to investigate, understand and monitor the potential impact of mobile phone use, given that there has been a surge in the mobile phone users globally in recent years, as well as a lack of data on mobile phone use covering a period for more than 15 years.

     In response to the three parts of the question, my reply, with consolidated input from the Department of Health (DH) and the Office of the Telecommunications Authority (OFTA), is as follows -

(a) OFTA has set up a dedicated page on its website on Radiofrequency Radiation Safety which provides relevant information for public reference.  OFTA has also produced information leaflets, booklets and posters on radiofrequency radiation to disseminate information about mobile phone safety among the public.

     In addition, the Centre for Health Protection website maintains a webpage which refers to the latest assessment of IARC.  This would help the public understand the relevant health effects and risks.

     As explained above, the health effects of mobile phone use requires further investigation.  However, if members of the public remain concerned, they may choose to adopt certain practices in their daily lifestyles to reduce exposure to radiofrequency electromagnetic fields, such as limiting the length of mobile phone calls, using hands-free devices that keep the mobile phone at a distance, as well as avoiding contact with the antenna when the phone is in use.  Such information is available on the websites of OFTA and Centre for Health Protection.

     Some members of the public may be particularly concerned that children and adolescents may be more vulnerable to the effects of radiofrequency electromagnetic fields, because this technology has been available to them from their early years.  In this regard, parents may decide on their own as to whether their children should avoid using mobile phones for unnecessary calls.

     DH will continue to keep in view the findings of reports and research on this subject, in order to keep abreast of the latest developments and the risks to public health.  DH will also offer professional medical advice to OFTA for consideration of regulatory issues.

(b) All mobile phones sold in the Hong Kong market must comply with the HKTA2001 specification issued by OFTA, namely "Compliance Test Specification - Safety and Electrical Protection Requirements for Subscriber Telecommunications Equipment".  The specification is set according to internationally recognised standards and covers the electrical safety requirements for telecommunications equipment, as well as the safety standards on radiofrequency electromagnetic fields for mobile phones.  

     According to the above specification, the level of radiofrequency electromagnetic fields from mobile phones must comply with either the safety limits imposed by the International Commission on Non-Ionising Radiation Protection (ICNIRP) or those by the American National Standards Institute/Institute of Electrical and Electronics Engineers (ANSI/IEEE).  Selling mobile phones that do not comply with such specification is a breach of the Telecommunications Ordinance and liable to prosecution.

     At present, OFTA operates the Telecommunications Equipment Evaluation and Certification Scheme with a view to better providing for the evaluation and certification of telecommunications equipment.  Under the scheme, manufacturers and suppliers apply for certification of mobile phones on a voluntary basis in order to prove that such products comply with the technical specifications concerned.  The vast majority of mobile phone brands sold in Hong Kong have applied for and acquired certification for their products.  OFTA has also published the "specific absorption rate" (SAR) of all certified mobile phones on its website for the reference of the public.  

     As data in respect of the level of radiofrequency electromagnetic fields from mobile phone products are readily accessible to the public via the Internet, OFTA has not, at this stage, considered requiring mobile phone manufacturers or suppliers to specify the relevant data on the packages of their products.

(c) The two standards on the safety limits of radiofrequency electromagnetic fields from mobile phones mentioned in the question refer to the aforementioned SAR limits promulgated by ICNIRP and ANSI/IEEE respectively.  These limits are adopted by OFTA as the safety standards on radiofrequency electromagnetic fields for mobile phones having consulted the Department of Health.  Since the two standards make use of different assessment methodologies and procedures, they cannot be compared directly.  Despite the difference, the safety protection offered by two standards is largely equivalent.

     In areas with poorer service reception, such as remote areas or obscured spots in urban areas, mobile phones may generate a higher level of radiofrequency electromagnetic fields.  However, even under such circumstances, the normal use of mobile phones will not result in exceeding the SAR limits prescribed in the safety standards on radiofrequency electromagnetic fields for mobile phones.  If members of the public remain concerned, they may consider using hands-free kits, avoid using mobile phones in areas with poor reception and shortening their mobile phone calls.

Ends/Wednesday, July 13, 2011
Issued at HKT 18:35