EMF ASSESSMENT BY MEASUREMENT (IVORIAN CASE ) GUY-MICHEL KOUAKOU Head of standardization service VICE-CHAIR OF STUDY GROUP 5 1 PLAN • National Context • EMF assessment • Flowchart for measurement • Measuring equipment • Post-processing analysis • Some statistics • Conclusion 2 NATIONAL CONTEXT • Major public concerns, misinformation about EMF health related issues and particularly EMF effects from base stations. • Many people are against the installation and deployment of base stations in their neighbourhoods. • No legal protection framework in place for EMF related health issues. • ATCI (National Regulatory Authority) ensures the need to protect human health by adopting international standards such as: – ITU-T recommendations for compliance and estimation of EMF (K.52, K.70) – ICNIRP (International Commission on Non-Ionizing Radiation Protection) recommendation for exposure limits – CEPT recommendation for measurement procedures (ECC(02) 04 revised) 3 EMF ASSESSMENT • Measurements campaign in the town of Abidjan (the capital). • Measurements were carried out in the 10 KHz to 6 GHz band • First step: 103 locations were identified for measurements but later restricted to 43 locations using a decision level of 0.3 v/m. • EMF Estimation for these locations were carried out using the EMF estimator (K.70) and technical characteristics of base stations at the varoius points. • In situ measurement: about 3 hours per location (1 month for all locations) • some words about measurement protocol – Based on three cases; – Case 1 for quick overview to find the point where the field is higher (1.1, 1.5, 1.7) – Cases 2 & 3 for detailed investigation which allow to scan variable frequency band to deal with specific services 4 FLOW CHART Exigences de protection de la santé respectée Résultats> limites CIPRNI Exigences de protection non respectée 5 MEASURING EQUIPMENT • For case 1: RF radiation meters with isotropic field probes and a dosimeter EMR 300 W/G (10 Khz - 3 Ghz) ANTENNESA EME SPY 120 (88Mhz - 3Ghz) • Cases 2 & 3: Spectrum Analyser EMF from différent services (TV, FM, GSM z…) Switch Tri axis Probe Spectrum analyser Anritsu MS2721B x x y z y 6 POST-PROCESSING (1/2) • Measurement uncertainty estimation according to IEC guide: • For each case equipment uncertainty was taken into account. CAS 2 Uncertainty of xi Input quantity Value (dB) Antenna Factor 2,00 Cable 0,20 isotropy 1,70 Receiver 2,00 distribution U(Xi)( %) Ci (CiU(Xi))2(%) normal 25,89 1,00 12,95 2,33 1,00 1,16 21,62 1,00 12,48 25,89 1,00 12,95 rectangular Combined standard uncertainty (66% ) 21,29 Expanded uncertainty (95 %) 41,74 IEC “Guide to the expression of uncertainty in measurement Ed. 1, 1995 7 POST-PROCESSING (2/2) • GSM measurement extrapolation was considered for maximum possible traffic. Measurements were done only for the permanent control channel. The extrapolation to the maximum traffic is then calculated by the following formula Emax = E Control Channel x sqrt (n Transmitteers) • The determination of « n » was done in accordance with typical base stations configurations. • For each location an extrapolation factor was estimated. 8 RESULT Every measurement was found to have been in compliance with ICNIRP limits. 9 SOME STATISTICS • The average field level per service E(V/m) 2,669 3 3 2 1,336 2 0,720 1 0,312 0,378 0,042 0,044 0,023 0,033 Exploration RADARS-BLR-FH DECT GSM 1800 RADARS -DAB GSM 900 TV PMR-BALISE FM PMR HF 0 0,241 0,015 1 was low (under 1V/m) except for GSM service where the average levels were 1.336 V/m for GSM 900 and 2.67 V/m for GSM 1800 Average field level per service • According to ICNIRP limits. E(V/m) 10% GSM 900 represent 3.31% and GSM 1800 represent 4.70% 8% 4,70% 6% 3,31% 2,57% 4% 0,86% 2% 1,12% 0,12% 0,62% 0,07% 0,07% 0,05% Exploration RADARS-BLR-FH DECT GSM 1800 RADARS -DAB GSM 900 TV PMR-BALISE FM PMR HF 0% 0,05% Ratio between average value and ICNIRP limits 10 SOME STATISTICS Exploration satellite, RADARS-BLRFH DECT GSM 1800 RADARS -DAB GSM 900 TV Bande IV et V 1%< niveau < 2% PMR-BALISE 2%< niveau < 5% • For GSM 1800 : 89 % of EM field Radio FM 5%< niveau < 10% was less than 10% of limits value (4 V/m) ; PMR 10%< niveau < 100% • For GSM 900 : 98 % of field levels service HF 100% 90% 80% 70% 60% 50% 40% 30% 20% 10% 0% was less than 10% of limits value (5.68 V/m); < 1% de la valeur limite Field level distribution per service 11 CONCLUSION • ATCI will work with GSM operators to reduce the level of exposure accordind to mitigation technics proposed by recommendation UIT-T K.7O. • ATCI will use EMF estimator to assess the compliance of base station before their installation. • K.GUIDE should include : – A detailed measurement procedure taking into account the work done by CEPT, CENELEC and IEC. – A procedure to choose relevants location for measurement – A methode to caculate extrapolation factor for GSM in multi-source and multioperators environment. 12 THANK YOU FOR YOUR ATTENTION ? 13