EDITORIAL A new y e a r w ith its hopes and expectations has com e a round again. W ill w e as physiotherapists be a ble to m ake a c o n tribution to the global goal o f h ealth fo r all by y e a r 2000, and a re we doing enough to p re p a re ourselves a nd fu tu re physiotherapists fo r the different role o u r profession will probably play in th e new S outh A frica? L et us be proactive and decide w hat will be necessary to m eet future challenges b efore som eone else decides on o u r role. A t a tim e w hen th e g reenhouse effect a nd pollution o f o u r planet is o f c oncern to everyone, physiotherapists m ust realise th at they too may need to m ake a con trib u tio n to improve the w orld's health. In th e article by E sterhuyse a nd Irw in -C am ith ers the effect o f a tm o s p heric dioxide and n itra te gases on th e respiratory system is investi gated. T h e a u th o rs found a decrease in the lung function o f children teste d d u e to th e pollution, and have suggested th at the acceptable lim its f o r a tm o s p h e r ic S O 2 a n d N O 2 n e e d t o b e r e d e f in e d . A s physiotherapists we d o n eed to becom e involved and lobby fo r a cle an e r environm ent to which o u r p atien ts m ust re tu rn w hen d is charged from o u r care. In o rd e r to m eet th e challenges o f first contact physiotherapists we n eed to give even g re a te r a tte n tio n to th e assessm ent o f o u r patients. It is im portant to find a n objective m ethod o f assessing especially in th e field o f neurology w here m any o f o u r evaluation techniques are subjective and n ot always reliable. In the study by M orton e t al the a u th o rs a nd selected physiotherapists experienced in the field viewed video recordings m ade o f c ere b ral palsy children w ho had undergone selective p o ste rio r rhizotom y. T hey found th a t it was n ot possible to objectively assess these children using video recordings which w ere not standardised and have recom m ended a form at to be used when making such recordings in the future. In the article by van d e r M erw e et al the safety and efficacy of ultrasound therapy is discussed. In th e experim ent undertaken it was found th a t energy distribution o f ultrasound is not c o nstant and the high spatial intensities within the beam may cause dam age to the pa tie n ts’ tissues. B ecause the effective radiating a rea (E R A ) which was m easured by the a u th o rs was consistently higher than the E R A rated by the m anufacturers, it is im p o rta n t to be aw are o f the dangers th a t could be associated with u ltrasound therapy, a m odality which is com m only used by physiotherapists. It behoves all o f us to e n su re th a t n ot only d o we tre a t o u r patients effectively but we m ust also use reliable and valid m ethods o f assess m ent before and a fte r trea tm e n ts. T he m odalities that we use must be safe and correctly applied and w hen o u r p atien ts a re ready for discharge we m ust a tte m p t to m ake su re th at they will b e a ble to cope in th eir com m unities to which they return. AN EVALUATION OF THE LUNG FUNCTION OF EIGHT TO TWELVE YEAR OLQ CHILDREN LIVING IN TABLE VIEW, CAPE TOWN W J Esterhuyse, B Sc (Physio), Lecturer, University of Stellenbosch S H Irwin-Carruthers, M Sc (Physio), Senior Lecturer, University of Stellenbosch ABSTRACT Two groups of twenty children between the ages of 8 and 12 years, who lived in areas near the petrochemical complex in Table View, were studied to ascertain the prevalence of respiratory disease. A random sample of 15children from each group was subjected to lung function testing using the ELF. Results showed a higher incidence of respiratory disease in the group living closer to the petrochemical complex, but the sample was too small to show any statistical signi ficance. There was no difference in lung function test results between the two groups, but both groups demonstrated lower values than the predicted norms for their age, weight and height. OPSOMMING Twee groepe, elk bestaande uit twintig kinders tussen die ouder- dom m e van 8 en 12 jaar wat woonagtig is in die omgewing van die petrochemiese aanleg in Table View, is ondersoek om die voorkoms van longsiektes te bevestig. 'n Ewekansige steekproef van 15 kinders uit elke groep is onderwerp aan longfunksietoetse met the ELF. Die groep w at nader aan die petrochemiese aanleg gewoon het, het 'n hoer voorkoms van longsiektes getoon, maar die steekproef was te klein om statistiese beduidenheid te toon. Daar is geen verskil in longfunksies tussen die twee groepe bewys nie, maar beide groepe het wel laer waardes as die verwagte norme in verhouding tot die onderskeie ouderdom, gewig en lengte bereik. INTRODUCTION D uring the last decade th e re has been an increasing aw areness of environm ental pollution and, in particular, o f the effects o f pollution on m an’s health and his c o ntinued existence. In the C ape Peninsula this problem is as pressing as elsew here. If o n e drives in the direction o f T able View and B loubergstrand th ere is always a visible cloud o f gaseous sm oke which varies in degree and shifts in position according to the wind direction. T hese gasses o rig inate in the petrochem ical industries in this area. M any children in the T able View, E dgem ead and Bothasig a rea undergo daily expo su re to the su lp h u r dioxide (S O 2), ozone (O 3) and n itra te (N O 2) gases p ro d u c ed .1 Physiotherapists and medical d o c to rs practising in these areas confirm th at local in h abitants to o a re c o ncerned a b o u t th e potential th rea t to th eir health caused by these p o llu ta n ts.1 A t the request o f local au th o ritie s and the D e p a rtm e n t o f H ealth, the CS1R conducted an epidem iological study during 1983, in which they investigated the effects o f air-pollution on the m ortality and m orbidity o f local in h ab i tants, with specific referen ce to respiratory problem s. N o statistically significant evidence o f increased m ortality was found in th e ex perim ental area. M orbidity was assessed by m eans o f notification o f respiratory diseases, com pletion o f qu estio n n aires and self-evalu- atio n o f th eir sym ptom s by previously identified bronchitis sufferers. An increased incidence o f re sp irato ry problem s was re p o rte d by people living in the experim ental area. In 1988 the D e p artm en t o f Physiotherapy, U niversity o f Stellen bosch, conducted a follow-up study aim ed at obtaining m ore o b jec * This article is based upon a group study performed by the following final year students at the University o f Stellenbosch: C Ferreira, L Fourie, N Jooste, D Olwage, E Relief E Sassenberg, C van der Westhuizen, K van Niekerk, R Vos B Sc (Physio) University o f Stellenbosch, 1988. Submitted February 1991, corrections received November 1991. Bladsy 2 Fisioterapie. Februarie 1992, dee/ 48 no 1 R ep ro du ce d by S ab in et G at ew ay u nd er li ce nc e gr an te d by th e P ub lis he r (d at ed 2 01 3. ) tive evidence o f the effects o f air-pollution on lung functions. This study w as conducted on children, as they a re considered to be m ore susceptible to th e damaging effects o f p o llutant gases whilst th eir lungs a re still developing p rio r to th e o nset o f puberty.2 T h e re is a growing belief th at respiratory disease in children predisposes to the developm ent o f respiratory m orbidity and early m ortality in the adult. R e p ea te d lung infections in th e child can lead to chronic airway disease. 3 O verseas studies 'o n th e effects o f environm ental factors on the re sp irato ry function o f children have d e m o n stra ted an increased incidence o f respiratory sym ptom s and decreased, pulm onary fu n c tion in environm ents w here th e re was a high percentage o f sulphur dioxide in th e air. Im provem ent in the quality o f the atm osphere resulted in reduction o f sym ptom s and increased lung function.4 P u re sulphur dioxide is regarded as a mild re sp irato iy irritant which causes u p p e r airway irritation. By stim ulating the sensory nerve endings in th e m ucous m em brane, inhalation o f S O 2 results in a burning sensation in the nose which inhibits respiration, acco m p a nied by coughing d u e to laryngeal irritation. Stim ulation o f the trigem inal nerve endings also causes burning o f the eyes with in creased te a r form ation. S O 2 can also act as a bronchoconstrictor, causing resistance to airflow accom panied by pain due to irritation o f th e bronchial m ucosa.5 W h e n S O 2 o c c u r s w ith h u m id ity , s u lp h u r ic a cid is f o r m e d .6 H 2S O 4, N O 2 and O 3 a re all pulm onary irritan ts a nd p e n e tra te to the low er airways, resulting in increased respiratory ra te a nd decreased tidal flow, presenting as dyspnoea.5 METHOD T h e sam ple was drawn from two well-delineated subdivisions of T able View, Sunridge and B loubergstrand. T hese two areas are occupied by families o f sim ilar socio-econom ic statu s and have the sam e prevailing winds, namely south-east (140-210°) and north-w est (280-350°). Sunridge lies closer to the petrochem ical complex and m ore directly in line with the prevailing so u th -e aste r which blows from th e direction o f the complex. B loubergstrand lies o utside the a rea o f visible pollution and the B loubergstrand sam ple was r e garded as the control group, although a certain level o f air-pollution c an n o t be excluded. C riteria for inclusion in the sam ple w ere th at the child had to be aged betw een eight a nd twelve years, have lived in the a rea c o n tin u ously fo r a t least five years and not have any cardiac problem s. Potential children for inclusion in the sam ple w ere identified by house to house visits and interviews with the parents. W hen a child w as identified as satisfying the criteria, the p a tents w ere requested to com plete a questionnaire (standardised q u estionnaire ATS D L D 78C ) which was collected the sam e evening. D ue to limited time, only 20 households in each area w ere identified. F rom the 40 q u e s tionnaires com pleted, thirty (15 from each a rea ) w ere drawn ra n domly a nd these children underw ent lung function tests. T esting was perform ed a t a central venue, by appointm ent. On arrival each child was weighed and m easured (barefoot). C areful explanation o f the lung function tests was given to the child, each child being tested a t least twice and up to four tim es if the child experienced difficulty. T h e child's best results w ere recorded. T he m easuring instrum ent used was the E L F (E lectronic Lung F u n c tions) apparatus, which was program m ed to recalibrate a u to m a t ically before each test. T he following param eters w ere m easured: • FV C (forced vital capacity) • F E V i (forced expiratory volume in 1 second) . F E V i% • F E F 25 (forced expiratory flow at 25% o f vital capacity) • F E F 50 (forced expiratory flow a t 50% o f vital capacity) • F E F 75 (forced expiratory flow at 75% o f vital capacity) • P E F R (peak expiratory flow speed) All m easurem ents w ere taken and com puted by the E LF , which gave an imm ediate print-out o f results and diagnosis. M ean and sta n d ard deviation w ere calculated fo r each param eter. An inde pe ndent o bserver (specialist in internal m edicine) identified tests which had been incorrectly p erform ed and these w ere excluded from th e results. Inform ation derived from th e questio n n a ire w as subjected to c o m p u te r analysis using th e R E F L E X program m e a nd results were tabulated. RESULTS In the results and discussion th e B loubergstrand sam ple (fu rth e r from the petrochem ical complex) is designated group A a nd the Sunridge sam ple (n e a re r to the petrochem ical com plex) is d esig n ated g roup B. T he ra tio o f boys to girls was 9:11 in group A a nd 6:14 in group B. T he m ean age o f th e-g ro u p A children was 10,2 years (range 8-12) and th at o f the group B children was 10,8 years (range 9-12). Questionnaires All 40 questionnaires w ere re tu rn e d com pleted. T h e re was a higher re p o rte d incidence o f respiratory disease in g roup B, but because the sam ple is so small no statistical significance can be atta ch e d to the differences in incidence o f the various specific d is eases (T able 1). Table 1: Incidence of respiratory disease in Group A (Bloubergrant) and Group B (Sunridge) children CONDITION G R O U P A GROUP B YES NO YES NO DHRONIC BRONCHITIS - 20 - 20 ACUTE BRONCHITIS - - - - ASTHMA 19 3 17 DTHER DISEASES IN 1ST 2YF 2 18 4 16 SINUSITIS 3 17 7 13 3RONCHIOUT1S - - - - 3RONCHITIS 4 16 9 11 ASTHMATIC BRONCHITIS 1 19 2 18 MIDDLE EAR INFECTION 7 13 11 9 TOTAL INCIDENCE 18 - 36 - N o difference was found betw een th e groups in th e o ccurrence o f the following signs: cough accom panying a cold, cough in the absence o f a cold, chest secretions in the absence o f a cold. G ro u p B showed a higher incidence o f chest secretions accompanying a cold. A higher incidence o f allergies a nd c roup was re p o rte d in group A but in both groups the num bers w ere very small. T h e re w ere slightly m ore sm okers in group B hom es (13:18) but no relationship was found betw een th e incidence o f asthm a and the n u m b e r of sm okers in the home. Lung function tests Table 2: Average values on lung function testing PARAMETER GROUP A GROUP B FEV1 93,5833 95,3846 FVC 104,917 107,077 FEV1% 89,6667 89,6923 FEF25 101,917 187,308 FEF50 82,3333 77,6462 FEF75 64,75 92,6923 PEFR 91,75 101,231 Physiotherapy, February 1992 Vol 48 no 1 Page 3 R ep ro du ce d by S ab in et G at ew ay u nd er li ce nc e gr an te d by th e P ub lis he r (d at ed 2 01 3. ) In g ro u p A the resu lts o f two children had to be excluded because they w ere unable to c a n y o u t the tests correctly. O ne gro u p B child refused to take th e tests, whilst a second child’s resu lts had to be excluded d u e to a m echanical fault. T h irte en sets of lung function tests in each group w ere thus available fo r analysis. F o r each child, th e resu lts w ere c o rrelated with his o r h e r age, weight a nd height and c a lc u la te d a s a p e r c e n ta g e o f t h e p re d ic te d v a lu e s a c c o rd in g to Schoenburg. 8 T able 2 com pares th e average values fo r the two groups. G raphic repre se n tatio n o f th e average perce n ta g e values reveals no significant differences in lung function betw een th e two groups (F igure 1). In both groups, however, th e F E V i, F E V i% a nd F E F 50 a re low er th an th e norm al average o f 100% p redicted by Schoenburg. O nly th e FV C in b oth g roups and the P E F R in gro u p B reach ed norm al values. 120 100 FVC FEV1 FEV1% FEF PEFR H S eries A W Series B Figure 1: Lung function values of 8 to12 year old children DISCUSSION AND CONCLUSIONS T h e higher re p o rte d incidence o f respiratory disease in g roup B children, w ho lived clo ser to th e petrochem ical complex, cannot be regarded as statistically significant d u e to th e small sam ple size. The higher incidence o f sm okers in g roup B parents may also have played a role in the higher incidence o f disease in this group. A lthough no co rrelation was found betw een the n u m b er o f sm okers in the house and the n u m b er o f children w ho suffered from asthm a, a previous study has shown th at ch ild ren ’s lung functions a re adversely affected w hen th e ir parents, and in p a rticu la r th e ir m others, sm oke . How ever, a study carried o u t in O h io 10 also show ed a hig h er re p o rte d incidence o f a cu te a nd c h ro n ic re sp irato ry disease in children a tte n d ing school in an area o f raised S O 2 a nd N O 2 levels. N o significant difference could be found betw een th e lung func tions o f th e tw o groups o f children, but b oth g roups d e m o n stra ted low er values th an th e pre d ic te d norm s.8 Since th e possibility o f a d e g ree o f a ir pollution in th e a re a o f th e c o n tro l g ro u p could n o t be excluded, a fu rth e r study o f a larg e r sam ple o f children from suburbs b o rdering on th e petrochem ical complex is recom m ended, with a c o n tro l g ro u p from fu rth e r afield. A lthough th e 1986 C S IR study o f th e a rea show ed pollution a t th a t tim e to be within acceptable lim its,1 M ostardi 10 has suggested th at th e a cc eptable limits fo r atm ospheric SO 2 and N O 2 be redefined. Acknowledgements T hanks a re re co rd e d to P ro fe sso r M A d e Kock, fo rm e r H e ad o f th e D e p artm en t o f Internal M edicine, U niversity o f Stellenbosch, for the provision o f th e E L F a n d fo r training in its use, and also to D r S W alsh o f th e sam e D e p a rtm e n t fo r h elp in analysing th e results. REFERENCES 1. Klopper JLM, Harrison JA, Rip MR. Epidemiological studies of health effects associated with air pollution in the G reater Cape Town area, Pretoria, CSIR, 1986. 2 LeederSR , Corkhill RT, Irwin LM e ta l. Influence o f family factors on the incidence o f lower respiratoiy illness d u rin g the first year o f life. B r J Prev Soc M ed 1976;30:203-212 3. Sharratt MT, Cherny F. Pulmonary function and health status:a pilot study 1971- 1974. Arch Environ Health 1979;34:114-119. 4. Kagawa JU N .Toshio MD, Toyama MD. Photochemical air pollution - its effects on re s p ira to ry fu n c tio n o f ele m e n ta ry school ch ild ren . A rch E nviron H ealth 1975;30:117-122 5. Alarie Y. Classification of airborne chemicals that stimulate respiratoiy tract nerve endings.O i/ R ev Toxicol 1973;2:229. 6. Saruc M, Fugas M, Hrustic O. Effects o f urban air pollution on school-age children. Arch Environ Health 1981;36:101-108. 7. Ferris BG. Epidemiology standardisation project. A m R ev Resp Disease 1978; 118(6) Part 2 8. Bouhuys A, Schoenburg JB, Beck, GJ. Growth and decay of pulmonaiy function in healthy blacks and whites. Resp Physiol 1978;33:367-393. 9. Ware JH , Dockeiy DW, Spiro A et al. Passive smoking, gas cooking, respiratoiy health of children living in six cities. A m R ev Resp Disease 1984;129:366-374. 10. Mostardi RA, Ely DL, Woebkenberg NR et al. The University of Akron study on air pollution and human health effects (1 & 2). Arch Environ Health 1981;36:243-255. CHARACTERIZATION OF THE ACOUSTIC OUTPUT OF THERAPEUTIC ULTRASOUND EQUIPMENT M G van der Meiwe (MSc Physics Stellenbosch) N Bhagwandin (MSc Physics Natal) J E van der Spuy B Eng Hons Stellenbosch) PRI e Roux (PhD Physics Cape Town). Directorate of Radiation Control SUMMARY The safety and efficacy of ultrasound therapy may be compromised if the output from therapy transducers differs considerably from the indicated value. Although the total power output of a transducer can be easily measured using a pressure balance, it is also important to know how this energy is distributed through space. B y'using a hydrophone scanning technique, beam profiles of the energy dis tribution can be obtained. From the beam profiles various parameters such a the effective radiating area (ERA) and the beam non-uniformity ratio (BNR) can be determined. Since the spatial-average intensity selected for treatment is a ratio of the emitted ultrasound power and the effective radiating area, it is essential to be able to measure parameters like the effective radiating area. In this study ERA and BNR measurements for commercially available devices were performed with a hydrophone scanning technique. OPSOMMING Die effektiwiteit en veiligheid van ultraklankterapie kan bevraagteken word indien die lowering vanaf terapie-omsetters betekenisvol afwyk vanaf die aangeduide waarde. Alhoewel die totale drywingslewering vanaf 'n omsetter maklik gem eet kan word met behulp van 'n drukba- lans, is dit 00k belangrik om te weet hoe die energie ruimtelik versprei is. Bundelprofiele van die energieverspreiding kan verkry word deur gebruik te maak van 'n hidrofoon-aftastings-tegniek. Vanaf die bun delprofiele kan verskeie parameters soos die effektiewe stralingsarea (ESA) en die nie-uniformiteitsverhouding van die bundel (BNV) verkry word. Aangesien die ruimtelik-gemiddelde intensiteit, w atgew oonlik as 'n behandelingsparam etergekies word, die verhouding tussen die uitgestraalde drywing en die effektiewe stralingsarea is, is dit van belang om parameters soos die effektiewe stralingsarea te kan bepaal. In hierdie studie is van 'n hidrofoon-aftastings tegniek g e bruik gem aak om ESAen BNV metings van kommersieel beskikbare terapie toestelle te verkry.________________________________________ DEFINITIONS E ffective radiating a rea (E R A ) m eans the a rea o f th e effective radiating surface that consists o f all points at which the ultrasonic Bladsy 4 Fisioterapie, Februarie 1992, deel 48 no 1 R ep ro du ce d by S ab in et G at ew ay u nd er li ce nc e gr an te d by th e P ub lis he r (d at ed 2 01 3. )