Factores que influyen en la calidad de servicio turístico

INTRODUCTION

M ention was m a d e in C h a p te r 3 o f a "hierarchy o f p ro te c tiv e measures" w h ich m ay b e d e p io y e d in th e prevention o f o c c u p a tio n a l disorders. It is tim ely, in this c h a p te r, to e n u n c ia te th a t hierarchy fully in order to p la c e th e w ork to b e described in context.

The preferred measures a re those w hich ore b rou g h t to b e a r b e fo re th e o c c u rre n c e o f a n y exposure to a causal a g e n t a n d in clu d e substitution, (which is n o t p ra c tic a b le in this case), a n d p ro p h y la c tic screening. These m a y b e te rm e d prim ary measures. Secondary measures seek to interpose e ffe c tiv e barriers b e tw e e n causal agents a n d susceptible individuals. They com prise measures w h ich are inherent to th e system o f work, such os c o n ta in m e n t a n d lo ca l exhaust ventilation (LEV), w hich d o not require a n y special e ffo rt or a c tio n on th e p o rt o f individual w o rkp e o p le . Tertiary measures consist o f th e use o f various personal p ro te c tiv e devices such os RPE w h ich require personal c o m p lia n c e a n d are subject to th e vagaries o f personal fit.

In this c h a p te r a series o f experim ents to address th e se co n d a ry p reve n tio n o f LA A in a strategic or system atic w a y is described. This w ork is o n e o f a series o f studies w h ich w e re carried o u t in UK p h a rm a ce u tica l co m p a n ie s in th e 1980's. Most o f th e w ork has re m a in e d unpublished, despite its u n d o u b te d v a lu e a n d im p o rta n ce .

Fortunately m uch o f th e useful inform ation to c o m e o u t o f these studies was presented a t m eetings a n d w id e ly discussed a t th e tim e by interested parties so th a t it has n o t b e e n w holly lost. The early findings o f interest, m ainly o b ta in e d as th e result o f a p ro g ra m m e o f o c c u p a tio n a l hygiene w ork a t ICI (Rackham , personal com m unications), ore now given in summary b e lo w b e ca u se th e y inform th e w ork presented in this c h a p te r a n d are th e subject o f further consideration in discussion in C hapters 8 a n d 9:-

1. In g e n e ra l terms, levels o f antigens (of LAA) are d e p e n d a n t on stocking density a n d anim al activity. The second is m ore im p o rta n t.

2. A nim al a ctivity is a ffe c te d by th e entry o f p e o p le into a nim al room s a n d e specially by th e ty p e o f work th e y d o there.

3. A ranking o rde r o f types o f work shows th a t high exposure is associated w ith experim ental activities (shaving, surgery, o th e r high stress procedures), in te rm e d ia te exposures ore associated w ith routine procedures (g a va g e , routine exam ination) a n d lo w exposures ore associated w ith anim al husbandry.

The w o rk here described exploits th e hygiene investigations, w h ich w e re u n d e rta ke n during p h a rm a c e u tic a l c o m p a n y building de ve lo p m e n ts, in order to prescribe experim ental studies to aid op tim a l a nim al c o n ta in m e n t a n d e ffic ie n t room design.

OBJECTIVES

1. To optim ise anim al room design in o rde r to ensure a n tig e n c o n ta in m e n t as fa r as reasonably p ra c tic a b le .

2. To assess th e p e rfo rm a n c e o f c o n ve n tio n a l c a g in g systems in relation to 1.

3. To assess th e p o te n tia l o f alte rn a tive c a g in g systems in e n h a n c in g o p tim a l a n im al room prote ctio n .

METHODS

The w ork described in this c h a p te r was specified by m e a n d Fisons anim al husbandry m anagers and, in consultation w ith engine e rin g personnel, was c o n tra c te d to Messrs. I DC Consulting Engineers, a n d was carried o u t by th e m in 1986/7. A full-size anim al room m ock-up was co n stru cte d a t Messrs I DCs premises a t S tratford-on-Avon a n d e q u ip p e d w ith sta n d a rd ra b b it c a g e s for testing purposes. Details are given a t th e e n d o f th e section.

C o n v e n tio n a l best design prior to this study is represented in Fig. 6.1. This design w as th e c o n s e q u e n c e o f earlier unpublished experim ental w ork carried o u t a t ICI in 1978-80 a n d th e design features h a d b e e n a d o p te d w id e ly elsewhere. M ain fe a tu re is th e ce n tra l v a la n c e fe e d in g c le a r air into th e room . In theory, this c le a n , c o o le r air is d raw n dow nw ards a n d spreads into th e c a g in g areas w h e re it b e co m e s w a rm e d a n d c o n ta m in a te d by anim als a n d Is th e n d ra w n in to a filtered exhaust system thus p ro te ctin g p e o p le w orking in th e room w h o will spend most o f their tim e w orking in th e zone sw ept b y c le a n air.

Whilst superior to p re c e d in g designs, th e system described a b o v e hod+not b e e n associated w ith a n y dim inution o f LAA w h e re installed a n d was know n to b e pron e to e n tra in m e n t o f c o n ta m in a te d e d d y currents in th e b re a th in g zones o f anim al ro om workers (see Fig. 6.1). Therefore, this "state o f th e art" design was taken as th e basis o f a series o f experim ents involving co n fig u ra tio n a l variations in a nim al ro om design w h ich variations w e re considered, in e ngineering terms, to h a v e p o te n tia l to o ffe r im p ro ve d co n ta in m e n t. These configurations are presented d ia g ra m m a tic a lly in cross-section in Fig. 6.2.

The experim ents used 12 d iffe re n t configurations a n d 2 nom inal air c h a n g e rates (20 a n d 40 c p h ). Effects w e re assessed using a c o m b in a tio n o f 1-m inute a n d 4-m inute sm oke pellets a n d h a n d -h e ld smoke generators. These did no t o f course g iv e q u a n tita tiv e d a ta but did a llo w a q u a lita tive p a tte rn o f p e rfo rm a n c e to be construed quickly so th a t a large n u m b e r o f test configurations m ight b e tested in rapid order.

Existing c a g in g was used in these experim ental systems. H ow ever these c o n v e n tio n a l c a g e s presented a series o f ventilation problem s in their o w n right since th e y w e re designed to b e free standing a n d n o t to b e in te g ra te d into a larger system o f directionalised ventilation. Therefore it b e c a m e a p p ro p ria te to consider h o w th e design o f ca g e s themselves m ight b e a lte re d to optim ise th e inte g ra tio n sought. The m o ck-u p design w hich was d e v e lo p e d for this purpose is shown d ia g ra m m a tic a lly in Fig. 6.3.

The m ain o b je c tiv e o f th e a b o v e studies was to optim ise th e steady-state conditions o f th e anim al room . At th e e n d o f these studies som e simple experim ents w e re p e rform ed to assess th e results o f disturbing th e steady state by:

1. in tro d u cin g individuals to stand in front o f c a g e racks to sim ulate observation o f animals:

2. re m o vin g perspex screening a t th e front o f th e c a g in g system to sim ulate an a n im a l accessing m anoeuvre.

INLET

1

•m

o n

Fig 6.1

"State of ttie Art" animal room configuration in cross-section showing a) inlet,

exhaust and theoretical airflow between and b) actual airflows.

1 .Cage flush to exhaust header 2. Cage recessed 3. As 1 plus top valence 4. As 1 plus Inclned valence 5. As 2 plus top valence 6. As 2 plus Inclined valence

EL

Fig.

12 experimental configurations tested In ttie study - cross-sections as Fig. 1 some

detail omitted for clarity.

(NB: Configurations 1-8 arrows indicate special fèaturas, configurations 9-12 -

arrows indicate available routes of airflow)

1

6

₁

à

Fig. 6.3

The test room was co n stru cte d o f studding o n d ply o n d glo ze d stro te g ico lly to % perm it outside observotion. Air entry o n d exhoust w e re os in Fig. 6.1. Room dimensions w e re 5 x 3 x 3M. C oges used w e re NICP-Al w ith A6 rock (robbit) w h ic h h o v e o p e n fronts, reor ventiiotion slots o n d o re o rro n g e d in rocks on o w h e e le d fro me. The co g e s h o ve front fitting fo o d o n d w o te r contoiners. For e xp e rim e n to l purposes, robbits w e re sim uloted by o m e to i c o n to in e r o f robbit-like proportions into w hich o lO W o u tp u t light b u lb wos inserted to represent th e therm ol effe cts o ttrib u to b le to th e onim ol.

Sm oke from pellets wos in tro d u ce d vio oir inlets to m im ic g e n e ro l oirfiow o n d by h o n d -h e ld g e n e ro to r to illustrote oirfiow o t specific points in th e room . It wos necessory to to ke co n sideroble c o re to b e o b le to interpret o u tco m e s o c c u ro te ly . Only th e first fe w seconds o f g e n e ro l oir flo w studies w e re o f b e n e fit since th e room ropidiy filled w ith smoke. Similoriy, lorge releoses o f smoke from generotors w e re olso unhelpful o n d very smoll releose oliquots w e re used.

RESULTS

The effect of airflow

The bose test ro te o f 20 c p h wos used in th e test co n fig u ro tio n b e co u se it is th e m inim um d e m o n d e d by th e Regulotions g overning onim oi husbondry. There w os no q u o iito tive d iffe re n c e in th e tests corried out o t 20 o n d 40 c p h in o n y o f th e 12 configurotions. Tests run o t up to 100 c p h in som e configurotions increosed tu rb u le n ce o t c o g e o n d v o le n c e edges thus e n h o n c in g spilioges o f c o n to m in o te d oir into p o te n tio l w orker breo th in g zones.

Sm oke tests

Figures 6.4-6.10 show th e oirfiow potterns, eddies o n d w orking notes fo r th e d iffe re n t configurotions. In "open" configurotions (Fig. 6.2, 1-6) oir flo w e d prefe re n tio lly oround th e sides, tops o n d bottom s o f c o g e rocks follo w in g th e line o f least resistonce o n d not e ffe ctive ly cle o rin g c o n to m in o te d oir from c a g e d oreos. Positioning o f th e c o g e rocks flush or recessed to exhoust headers h o d no e ffe c t on oir flo w potterns. V oionces h o d no e ffe c t on oirfiow potterns o r eddies e x c e p t th o t inclined voionces increosed e d d y form otion. "Closed" config u ro tio n s (Fig. 6.2, 7-12) fo rc e d oir to flo w th rough c o g in g o n d c re a te d b e tte r scouring o n d unidirectionol flow . Eddies, bringing c o n to m in o te d oir b o c k

into th e w o rke r breathing zone w e re present in all configurations e x c e p t those w h e re c a g e fronts w e re screened by perspex sheets. Thus, th e g re a te r th e e le m e n t o f "closure", th e b e tte r th e result.

C aging Design

Fig. 6.11 shows th e airflow patterns associated w ith c o n v e n tio n a l c a g in g a n d th e e ffe c t o f b e tte r m a tch in g inlet a n d exhaust apertures in an e xp e rim e n ta l design. This was also m im icked by th e use o f perspex sheeting os p o rt o f th e configurations 10-12 a b o v e . C o n ta in m e n t was m uch im p ro ve d b y th e