Transcript SARs - ITU

Challenges of Mobile Phone SAR
Enforcement in Africa
Dr. Ally Y. Simba
Tanzania Communications Regulatory
Authority
Introduction
Many people want to know:
Are mobile phones safe?
Are base station safe?
ITU Workshop on tackling climate change and SAR Measurement: Benin, July 19, 2011
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EMF Exposure Safety
General Conclusion of Expert Scientific Reviews

According to International guidelines, the only
scientifically established adverse health effect
of RF energy in the human body is thermal, and
its safety limits are given based on Specific
Absorption Rates (SARs)

No credible evidence that RF exposure within
Internationally accepted limits causes any adverse
health effects
ITU Workshop on tackling climate change and SAR Measurement: Benin, July 19, 2011
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SAR Basics
Specific Absorption Rate (SAR)
is the rate at which RF energy is absorbed per
unit mass of a biological body
where ,  are conductivity and density
 | Et | 2
SAR 
[W/kg] of the material, respectively and Et is the

total electric field in a biological body
 SAR and Temperature Relationship
Pennes bio-heat equation
Here T represents the temperature of the tissue in degrees Celsius, ρ is the material
density (kg/m3), c is the heat capacity (J/kg/oC), k is the thermal conductivity
(W/m/°C), w is the perfusion by blood (mL/g/s), and Qm is the heat generated by
metabolism(W/m3). The term Tcore represents the core, or arterial, temperature of the
body.
SAR Basics
 SAR depends on the following
Incident field parameters
- frequency, intensity, polarization
source-object configuration (near- or
far-field)
Characteristics of the exposed body
- size, internal and external geometry
electrical properties of various tissues
Ground effects and reflector effects of the
objects in the field near the exposed body
 Averaged SAR
SAR is usually averaged over a certain
weight
 10-g Averaged SAR
 Whole
Body Averaged SAR (WBA-SAR)
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ITU Workshop on tackling climate change and SAR Measurement: Benin, July 19, 2011
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Mobile SAR Limits According
to ICNIRP Guideline
 Localized Exposure
 Mobile phone exposure is categorise as localized
exposure, i.e., only part of the body is exposed during
use
 The safety limit of the localized exposure, according to
ICNIRP is given:

General Public:
10-g averaged SAR = 2 W/kg
 Occupational:
10-g averaged SAR = 10 W/kg
ITU Workshop on tackling climate change and SAR Measurement: Benin, July 19, 2011
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Mobile SAR Limits According
to ICNIRP Guideline
 The limits were obtained based on the eye
experiment
– Human eye is about 10-g
– Because of the lack of blood flow in the eye,
there is low heat dissipation
– Considered to be a part that is most affected
in body
ITU Workshop on tackling climate change and SAR Measurement: Benin, July 19, 2011
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Mobile Phone SAR Enforcement
Mobile phone manufacturers are required to
ensure that their phones comply with these
objective limits for safe exposure
Manufactured phones, before put in to market
they must under go a compliance test
Phone considered safe to be legally sold in the
US and EU have FCC ID and EC mark in the
phone case, usually below the battery
The SAR values of mobile phones are available
on the internet or you can find them on the
specification sheet when you buy it
ITU Workshop on tackling climate change and SAR Measurement: Benin, July 19, 2011
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SAR Enforcement in Africa
 Enforcement base on manufacturer
compliance test and FCC or EU marking in
the SAR the phone works fine in US, America
and other country where strong legal systems
exist, and illegal importation is almost
impossible
 However, this approach is not effective in
most of the African countries
ITU Workshop on tackling climate change and SAR Measurement: Benin, July 19, 2011
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SAR Enforcement in Africa

The case of Counterfeit Phone
The cell of counterfeit phone is growing problem in Africa
These fake handsets are manufactured in a back office some
where in Asia and make their way to Africa countries
Due to this fact, manufacturer compliance test cannot be used
as an enforcement mechanism because even SAR value
indicated in these phone may be also fake
This problem has increased public anxiety to the public on
the safety of mobile phones
It should be noted here that, the SARs of counterfeit phones
do not necessarily exceed the safety limits
ITU Workshop on tackling climate change and SAR Measurement: Benin, July 19, 2011
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Possible Solution

The regulators should provide measured SAR
of phones in the market annually

This can be done by taking sample phone in
the market

Compare the SAR values in the phone manual
and measured ones

Inform the public of this information through
seminar, workshop and stake holder meeting
and by publishing them in the website for public
to access
ITU Workshop on tackling climate change and SAR Measurement: Benin, July 19, 2011
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SAR Measurements Approach I
 Regulators need to build Type Approval Laboratories (TAL)
with mobile phone SAR testing capabilities
 This is very expensive project, you will need at least the following
facilities and equipments. Most of these equipments are very
expensive
- EMC Chamber
- Mobile Phone Base Station Simulator
- SAR Measurement System
ITU Workshop on tackling climate change and SAR Measurement: Benin, July 19, 2011
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SAR Measurements Approach I
Taken from EMF Explained Series
 For example; SAR testing System alone cost up to
€ 400,000 EU and annual cost of € 100,000 for maintenance
and calibrations depending on the number of accessories
SAR Measurements Approach I
 Good news is less expensive testing system are developed.
 Some of this do not required expensive industrial-sized robot like
those used in the conventional system, hence less expensive
SARA – C (Index SAR, UK)
iSAR system (SPEAG, Switzerland)
ITU Workshop on tackling climate change and SAR Measurement: Benin, July 19, 2011
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SAR Measurements Approach II
 SAR measurements foreign laboratory
 In this case the regulator will collect sample phones from the
market and send them to foreign country for measurements
 Although the cost for SAR measurement per phone has not
been determine yet, this may be the short solution as the
regulators are building long term solution of building long term
capacity in equipment and human resource
ITU Workshop on tackling climate change and SAR Measurement: Benin, July 19, 2011
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Conclusion
The issue of mobile phone generate a lot of
anxiety to public in many African Countries

In order to minimize the public anxiety, the SAR of
of the mobile phone should be measured and the
values made available to the general public

There is no short cut in the SAR measurements in
Africa, Regulatory bodies should buy and install SAR
Measurements Systems or outsource the exercise in
foreign countries for few phones sampled in their
market so that to satisfy the public
ITU Workshop on tackling climate change and SAR Measurement: Benin, July 19, 2011
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Thank you for your kind attention
contact: [email protected]
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