Effects of industrial air pollution on wildlife

EFFECTS OF INDUSTRIAL AIR POLLUTION WILDLIFE

ON

JAMES R. NEWMAN

Environmental Science and Engineering, Inc., P.O. Box 13454, University Station, Gainesville, Florida 32604, USA

ABSTRACT

Air pollution is a recognised health hazard for man and domestic animals. Although industrial air pollutants have been known to cause sickness and death of the latter for over 100 years, little attention has been paid to their importance in the decline of wildlife. This paper reviews the existing information on the effects of industrial air pollutants on vertebrate wildlife. Air pollutants have had a worldwide effect on both wild birds and wild mammals, often causing marked decreases in local animal populations. The major effects of industrial air pollution on wildlife include direct mortality, debilitating industrial-related injury and disease, physiological stress, anaemia, and bioaccumulation. Some air pollutants have caused a change in the distribution of certain wildlife species.

INTRODUCTION

Numerous factors, including pesticide poisoning, habitat destruction, introduction of exotic species, and overhunting have been responsible for the decline in wildlife populations (Office of Endangered Species and International Activities, 1973). Air pollution is recognised as a major human health hazard but little attention has been given to its harmful effects on wildlife. Nevertheless, there are numerous reports of widespread sickness and death of domestic animals attributable to industrial air pollutants (Lillie, 1970; Newman, 1975). Often these episodes occur in rural areas where exposure of large numbers of wildlife to air pollutants may also be likely. The objectives of this article are to consider the impact of air pollutants on terrestrial wildlife and its contribution to the decline of vertebrate populations. Information is based on a review of available information and a recent study of the problem in Czechoslovakia supported by the National Academy of Science. 181 Biol. Conserv. (15) (1979)--© Applied Science Publishers Ltd, England, 1979 Printed in Great Britain

182

JAMES R. NEWMAN INCIDENTS PRIOR TO 1960

Air pollution has increased markedly since the Industrial Revolution of the 1850s. Episodes involving the sickness and death of domestic animals were reported as early as the 1870s and frequently through the turn of the century (Table 1). This problem was significant enough in England for a Royal Commission to be established in 1878 to investigate the livestock losses to farmers by air pollution (Royal Commission, 1878). TABLE I EARLYINCIDENTSINVOLVINGTHEADVERSEEFFECTSOFINDUSTRIALAIRPOLLUTANTSONDOMESTICANIMALS Date

Location

Pollutant(s)

Effects

1873 England 1878 England

Sulphurdioxide Deathof cattle Smoke Blinding of cattle near copper works 1908 Montana, A r s e n i c Widespread sickness and death USA to cattle and horses 1914 England Industrialsmoke Respiratoryproblems in cattle and reduced wool production in sheep 1915 California, Lead Widespread respiratory USA problems in horses near smelter 1930 Belgium Smokeand fog Deathof cattle from respiratory failure 1931 Austria Iron-containing Stomachand intestinal flue gases disorders in cattle 1935 Italy Fluroide Death of cattle and goats 1939 Germany

Arsenic

Widespread sickness in cattle, sheep, horses and p o u l t r y

Rejerence

Schwabe (1969) Royal Commission (1878) Formad(1908); Harkins & Swain (1908) Anon.(1914) Haring & Meyer (1915) Alexander (1931); Rubay (1932) Henneman (1931) Bardelli & Menzani (1935) Bischoff(1939); Wiemann (1939)

Air pollution incidents involving wildlife have been noted in the past, but they are less frequent and poorly documented compared with those involving domestic animals (Table 2). One of the earliest wildlife reports describes the death of fallow deer D a m a dama in 1887 as the result of arsenic emissions from a silver foundry in Germany (Tendron, 1964). In England at the end of the last century air pollution had caused such widespread changes in the natural environment that 'industrial melanism' was commonly reported in many scientific journals (Kettlewell, 1973). Although widespread sickness and death of domestic animals in the first quarter of this century have been documented there are no reports discussing injury or death of wildlife from industrial emissions. Yont & Sayers (1927) reported the death of large numbers of birds and other animals by hydrogen sulphide fumes in the vicinity of a Texas oil field but few details were given. One of the most detailed reports on the harmful effects of air pollution on wildlife is from Germany. Widespread killing of game animals by arsenic emissions

183

AIR POLLUTION AND WILDLIFE

TABLE 2 INCIDENTS PRIOR TO 1960 INVOLVINGTHE ADVERSEEFFECTSOF INDUSTRIALAIR POLLUTANTSON VERTEBRATE WILDLIFE

Date

Location

Species

Pollutant(s) type

1887

G e r m a n y Fallow deer

Arsenic

1927

Texas, USA

Hydrogen sulphide

1936

G e r m a n y Rabbits, red and roe deer

Arsenic

1957

Utah, USA

Fluoride

Small birds

Mule deer

Concentration NA

Effects

Death of fallow deer Up to Death of large 139/059 #g/m 3 number of birds NA Death of 60--70 ~ / o f game populations 1500 ppm in Fluorosis premolar

ReJerences Tendron (1964) Yont & Sayers (1927) Prell (1936)

Robinette et al. (1957)

NA = Not available.

occurred in the Tharandt forest in 1936. Between 60 ~oto 70 ~o of the red deer Cervus elephus, roe deer Capreolus capreolus and wild rabbits Oryctolagus cuniculus died. The deer exhibited defective hair growth and antler formation, cirrhosis of the liver and spleen, and emaciation (Prell, 1936). In 1957 the first reports of industrial fluorosis in Utah mule deer Odocoileus h. hemionus were published (Robinette et al., 1957).

INCIDENTS SINCE 1 9 6 0

Along with the greater environmental awareness of the late 1960s has come an increase in the number of reported incidents involving injury and death of wildlife from industrial air pollution (Table 3). Harmful effects on birds and mammals from North America, Europe, Africa and Japan have been observed for a variety of pollutants ranging from heavy metals to gases. These include death, debilitating industrial-related injury and disease, bioaccumulation of air pollutants, physiological changes associated with stress, and population declines. Reports of large die-otis of wildlife are not common. However, in 1971, a heavy fog combined with high sulphur emissions from a pulp mill in Canada killed between 200 and 500 songbirds. The birds exhibited inflammation of intestinal tracts and haemorrhages in the brain and trachea (Harris, 1971). Reports of industry-related debilitating diseases are more common. Hail & Masek (1969) reported the loss of balance and hair in red deer Cervus elaphus and roe deer Capreolus capreolus caused by arsenic emissions in Czechoslovakia. These debilitating effects contributed to the freezing to death of these deer during the winter. Industrial fluorosis has been found to exist in white-tailed, black-tailed and mule deer populations of Canada and the United States. In black-tailed deer

184

JAMES

R.

NEWMAN

== "~.~ .n> ,'r'

~ m

a., ~

=

~" r--

~" - ~ " _Z_

~r-

o', m

o,.& oo, 0

~.~ ~ ~

,1

. . . . . ::

z

•=

z~z

~Z

~

~=

'-,a~

0

0

,,n

zz

< "0

= ~.~

>

.,=

Z 0 0 Z <

~

~C

c~ C

o

0

. = ' u ~ ta

O o~ 0 eO 0

.= = ' g ~ °

~ ° = o o

~a e~

~

-o

E~

N

0¢'~ ~N m

M <

._= e~ o

0

0"--

N~

0

0 " ~

ZD

e~

e~

ngr,.

Zz

Z

0

0

~

~

~,

!~

~"0

&D~

£ N > e~ <

•

0,.~

... o

0

o

m

.o'~

.. 0

. . . . .

=.-~

z

e,q=

c

o

~

C

> >

z Z

egg

oo=

.~

~

~=~

~

~,

0

~z

Z

~J

mr,.)

>

o

, {

N

<

d

<~

=~

o~ I~.--

z

'-

>

od

g.~ {e

ii

~

~

,~

°° r , ) r...)

0

z II < Z

AIR P O L L U T I O N A N D W I L D L I F E

185

Odocoileus hemionus columbianus severe deterioration of the teeth including pitting, chipping and excessive tooth wear was observed in young as well as in old animals (Newman & Yu, 1976). In white-tailed deer Odocoileus virginianus, besides dental disfigurement, a high incidence of jaw fracturing was observed (Karstad, 1967). In mule deer Odocoileus h. hemionus lameness was reported (Kay et al., 1975). Asbestosis has been found in free-living baboons Papio sp. and rodents Rattus namaquensis in the vicinity of asbestos mines in South Africa (Webster, 1963). Respiratory damage has been noted in house sparrows Passer domesticus from urban areas of California (Wellings, 1970). The harmful effects of air pollution have been observed at great distances from their source. A high incidence of total and partial blindness has been found in a herd of bighorn sheep Ovis canadensis in the San Bernadino Mountains of California. This incidence of blindness in bighorn sheep occurred in a region with the highest concentration of oxidants. These known eye irritants have their source over 160 km away in Los Angeles (Light, 1973). Higher than normal levels of lead have been found in the vole Microtus montanus from other mountainous areas of California. Again the source of the pollution has been from distant urban areas (Hirao & Patterson, 1974). A number of air pollutants are known to concentrate in the tissues of wildlife. Fluoride has been found in high concentrations not only in the bones of deer (Karstad, 1967; Kay et al., 1975; Newman & Yu, 1976) but also in cottontail rabbits Sylvilagusfloridanus, hares Lepus sp., muskrats Ondatra zibethica, ground squirrels Citellus columbianus, woodchuck Mormota monax, deer mice Peromyscus sp., voles Microtus sp. (Gordon, 1969a; Karstad, 1970) and sparrows Passer domesticus (Balazovfi & Hluchan, 1969). High fluroide concentrations have also been observed in carnivores such as the red fox Vulpesfulva (Karstad, 1970) and the barn owl Tyro alba (personal observation). Cadmium levels four times higher than normal have been found in house sparrows in Japan and a high mortality recorded (Nishino et al., 1973). High levels of cadmium have also been found in the tissues of wild rabbits Syh, ilagus nuttali, ground squirrels Citellus columbianus and cricitid rodents near a smelter in Montana (Gordon, 1969b). Sparrowhawks Accipiter nisus and song thrushes Turdusphilomelos, living near a lead zinc smelter in England, accumulated high levels of cadmium in their body tissues (Martin & Coughtrey, 1975, 1976). The effects of this trophic transmitted cadmium were not known. Airborne mercury from a chlor-alkali plant in England has been found to concentrate in the tissues of several small mammals (Apodemus sylvaticus and Clethrionomys glareolus) (Bull et al., 1977). With a few exceptions, the effects of this bioaccumulation are not known. Some of the most extensive studies on the effects of air pollution on wildlife have been conducted in Czechoslovakia. These studies have revealed changes in the physiology and ecology of wildlife exposed to high air pollution. Western Czechoslovakia is a region of heavy industry with widespread air pollution by sulphur dioxide, nitrogen oxides, fly ash and cement dust, and also intensively-

186

JAMES R. N E W M A N

managed game populations. Detailed studies on the health of wild hares Lepus europaeus have been carried out by Novfikovfi and her co-workers at the Institute of Landscape Ecology. Hares from areas of high sulphur dioxide and fly ash have a more acid urine compared with hares from pollution-free areas. Animals from areas with heavy cement dust have a more basic urine (Novfikovfi, 1970). In addition changes in the calcium-phosphorus ratio of the blood are also observed. In areas of heavy sulphur dioxide and fly ash there is calcium deficiency close to a hypocalcemic condition. This difference is greater in younger hares and adult females. The concentration of phosphorus in the blood increases in adult hares, especially males (Novfikovfi & Roubal, 1971). Associated with variations in calcium and phosphorus levels in the blood of hares are changes in the erythrograms of these animals. Hypoproteinesis is found in hares from areas of heavy air pollution, including declines in albumins, ~-globins and 7-globins. These changes in erythrograms are comparable with those observed in animals with infections or allergic reactions (Novfikovfi et al., 1973). Along with these are changes in the age structure of these hare populations. In regions of high sulphur dioxide and fly ash the ratio of oneyear-old hares to adult hares is 30 ~ below that observed in pollution-free areas. In areas with heavy cement dust the ratio of one-year-old hares to adult hares is 35 ~o greater than control areas (Novfikovfi, 1969). Effects on the population ecology of wildlife have been observed in other studies. Rodent populations were lower than expected in an asbestos mining area of South Africa (Webster, 1963). In mountainous areas of southern California with the high oxidant concentrations population densities of small mammals were found to be less than in cleaner areas (Kolb & White, 1975). A reduction in passerine bird populations was found in the vicinity of an aluminium-producing plant in Czechoslovakia (Feriancov~-Masfirovfi & Kalivodovfi, 1965; Newman, 1977). Miyamoto (1975) reported the decline of lark populations in Japanese cities with heavy air pollutions. In London over the last 70 years there has been a decline and subsequent return of bird populations, especially hirundines, to the inner city. This has been attributed to the reduction of the once high levels of smoke and other pollutants in central London (Cramp & Gooders, 1967; Gooders, 1968). The house martin Delichon urbica appears to be a sensitive biological indicator for air pollution. This insectivorous migratory bird nests on the houses of villages and cities of Europe and Britain. Population censuses of the house martin in Czechoslovakia have shown the species to be rare or absent in areas with heavy fluoride, sulphur dioxide, fly ash, cement dust or nitrogen oxide pollution. Its numbers were 60~o lower in moderately-polluted areas than in control areas (Newman, 1977; Newman & Novfikov~, 1977). As a migratory species it has avoided potentially suitable nest sites in areas of heavy pollution in favour of cleaner areas. Air pollutants have also been found to have some unexpected effects on wildlife populations. In Czechoslovakia, nematode infections of pheasants Phasinus colchicus and protozoan infections of hares are less prevalent in areas of heavy air

AIR P O L L U T I O N AND WILDLIFE

187

pollution. When sulphur dioxide exceeds 0.15 mg/m 3 and fly ash concentrations are between 150-300 tons/km2/year, the incidence of syngamosis (gapeworm disease) in pheasants declines by 50 ~o. At sulphur dioxide levels above 0.35 mg/m 3 and fly ash levels above 501tonnes/km2/year nematode infections disappear altogether (Novb,kov~ & Tremmlovh, 1973). The incidence of coccidiosis in hares shows a similar relationship. Although the cause for the decline in the incidence of syngamosis is not known it is suspected that the intermediate hosts of nematodes are adversely affected by sulphur dioxide and fly ash, thereby reducing the chance for infection in pheasants (E. Novhkov~, pers. comm.).

CONCLUSIONS

Over 100 air pollution episodes have been reported since the end of the 19th century involving domestic and free-living animals (Lillie, 1970; Newman, 1975). Seventyfive percent of these episodes have been recorded in the last 25 years. This trend is the result of a better understanding of air pollution problems, broader communications and a greater interest in reporting such incidents rather than the result of a recent decrease in air quality. Approximately one quarter of these reported incidents involve vertebrate wildlife. These few reports are more a function of economic bias to report injury and death of domestic animals than the resistance of wildlife to air pollution injury. For example, in the early 1900s Harkins & Swain (1908) and Formad (1908) reported the injury and death of several thousand cattle and horses in rural Montana caused by arsenic emissions from a smelter. No mention was made of injury or death to deer or other wildlife plentiful in the area although deer and other wildlife species are known to be sensitive to arsenic emissions (Prell, 1936; Tendron, 1964; Hais & Masek, 1969). The majority of wildlife incidents reported involve deer and small birds (Tables 2 and 3). These groups are not necessarily more sensitive but are more likely to be monitored. This is especially true of deer, which is a widely managed game species. The status and health of small birds are not only of scientific but also of widespread public concern. Available information is too sketchy to draw conclusions concerning species sensitivity. The symptoms of injury observed in wildlife for pollutants such as arsenic, fluoride, and oxidants are similar to those observed in laboratory and domestic animals. For most industrial air pollutants information is lacking and few studies have reported ambient concentrations of the chemicals involved. High levels of airborne cadmium, fluoride, lead and mercury in the tissues of wildlife have, however, been reported. For the most part, the effects of such accumulations have not been investigated. The effects of air pollutants on wildlife can be dramatic, such as the die-off observed by Harris (1971), or quite subtle, such as those observed by Nov~kov~ and her co-workers in hares. In many cases the effects have been debilitating injuries,

188

JAMES R. NEWMAN

often c o n t r i b u t i n g to the d e a t h o f animals d u r i n g p e r i o d s o f n a t u r a l stress. I n d u s t r y related diseases such as fluorosis a n d arsenic p o i s o n i n g are c o m m o n . S o m e air p o l l u t a n t s (e.g. s u l p h u r d i o x i d e a n d fly ash) p r o d u c e s y m p t o m s similar to p h y s i o l o g i c a l stress a n d a n a e m i a . These c o n d i t i o n s also lower the chances o f survival o f wildlife d u r i n g times o f n a t u r a l stress. W h e r e p o p u l a t i o n m e a s u r e m e n t s have been t a k e n significant reductions in v e r t e b r a t e wildlife have been c o r r e l a t e d with industrial air pollution. The i m p o r t a n c e o f industrial air p o l l u t i o n as a factor c o n t r i b u t i n g to the decline in wildlife p o p u l a t i o n s should n o t be u n d e r e s t i m a t e d . ACKNOWLEDGEMENTS I w o u l d like to t h a n k the U S E n v i r o n m e n t a l P r o t e c t i o n Agency, the N a t i o n a l A c a d e m y o f Science and the C z e c h o s l o v a k A c a d e m y o f Science for their p a r t i a l s u p p o r t o f this study. I wish especially to t h a n k the Institute o f L a n d s c a p e Ecology, Prague, in p a r t i c u l a r D r E. H a d a c a n d D r E. Nov~ikovfi, for their h o s p i t a l i t y a n d discussions on biological i n d i c a t o r s o f air pollution. Finally, m y t h a n k s are due to E n v i r o n m e n t a l Science a n d Engineering, Inc. for assistance in p r e p a r a t i o n o f this paper.

REFERENCES ALEXANDER,J. (1931). Fatal Belgian fog. Science, N.Y., 73, 96. ANON. (1914). Smoky air and animals. Scient. Amer., 3, 299. BALAZOVA,G. & HLUCHAN,E. (1969). Der Einfluss yon Fluorexhalten auf die Tiere in der Umgebung einer Alumininumfabrik. Proc. Eur. Congr., Influence Air Pollut., 1st, Wageningcn, 1968, 41-8. BARDELLI, P. & MENZAN1,C. (1935). Studies of spontaneous fluorosis in ruminants: A note on prophylaxis. Annali d'Ingiene sperimentale, 45, 399-404. BISCHOEF,O. (1939). Poisoning of domestic animals through copper and arsenic containing fly dust. Dt. Tieriirztl. Wschr., 17, 442-7. BULL, K. R., ROBERTS,R. D., INSKIP,M. J. & GOODMAN,G. T. (1977). Mercury concentrations in soil grass, earthworms and small mammals near an industrial emission source. Environ. Pollut., 12, 135-40. CRAMP, S. & GOODERS,J. (1967). The return of the house martin. Lond. Bird Rep., No. 31, 93-8. FERIANCOV~,-MASAROVA,Z. & KALIVODOV~.,E. (1965). Niekolko poznamok vplyve fluorovych exhal~itov v okoli Hlinikarne v Ziari nad Hronom na kvantitu hniezdiacich vtakov. Biologia, Bratisl., 20, 341-6. FORMAD,R. J. (1908). The effect of smelter fumes upon the livestock industry in the Northwest. Rep. US Bur. Anim. Ind., 25, 237-68. GOODE~, J. (1968). The swift in central London. Lond. Bird Rep., 32, 93 8. GORDON, C. C. (1969a). Cominco America~ Report II. Department of Environmental Studies, University of Montana, Missoula. GORDON, C. C. (1969b). East Helana Report. Department of Environmental Studies, University of Montana, Missoula. HAIS, K. & MASEK,J. (1969). Effects of some exhalations on agricultural animals. Ochr. Ovzduzi, 3, 122-5. HARING,C. M. & MEYER,K. F. (1915). Investigation of livestock conditions and losses in the Selby smoke zone. Bull. U.S. Bur. Mines, 98, 474-520. HARKINS,W. D. & SWAIN,R. E. (1908). The chronic arsenical poisoning of herbivorous animals. J. Am. chem. Soc., 30. 928-46.

AIR POLLUTION AND WILDLIFE

189

NOVAKOV/~,E. & ROUBAL,Z. (1971). Taux de calcium et de phosphore dans le st~rum sanguin des li6vres expos6s aux pollutions de l'air. A ctes Congr. Un. int. Biologistes du Gibier, Paris, 3-7 mai 1971, 10th, 529-36. NovAKowk, E. & TREMMLOVA,B. (1973). Influence de la pollution de rair sur la syngamosis du faison commun. Actes Congr. int. Biologistes du Gibier, Paris, 3-7 mai 1971, 10th, 389-94. OFFICE OF ENDANGERED SPECIES AND INTERNATIONAL ACTIVITIES(1973). Threatened wildlife of the United States. Washington, Bureau of Sports Fisheries and Wildlife, US Department of Interior, Resource Publ., 114. PRELL, H. (1936). Die Sch~idigung der Tierwelt dutch die Fernwirkungen von Industsriealgasen. Arch. Gewerbepath. Gewerbehyg., 7, 656-70. HARRIS, R. D. (1971). Birds collected (die off) at Prince Rupert, B.C., September 1971. Canadian Wildlife Service, unpublished report, 1 October 1971. HENNEMAN, J. (1931). Frequent occurrence of stomach and intestine diseases in cattle caused by iron containing flue gases. Wien, Tieriirztl. Monatsschr., 18, 225-31. HIRAO, Y. & PATTERSON, C. C. (1974). Lead aerosol pollution in the High Sierra overrides natural mechanisms which exclude lead from a food chain. Science, N.Y., 184, 989-92. KARSTAD, L. (1967). Fluorosis in deer (Odocoileus virginianus). Bull. Wildl. Dis. Ass., 3, 42-6. K ARSTAD,L. (1970). Wildlife in changing environment. In Environmental change,focus on Ontario, ed. by D. F. Elrich, 73-80. New York, Simon & Schuster, Inc. KAy, C. E., TOURANGEAU,P. C. & GORDON, C. C. (1975). Industrial fluorosis in wild mule and whitetail deer from western Montana. Fluoride, 8, 182-91. KETTLEWELL, B. (1973). The evolution ofmelanism. Oxford, Clarendon Press. KOLB, J. A. & WHITE, M. (1975). Small mammals of the San Bernadino Mountains, California. SWest. Nat., 19, 112 14. LXGHT, J. T. (1973). Effects of oxidant air pollution on forest ecosystems of the San Bernadino Mountains. In Oxidant air pollution effect on a western coniferous forest ecosystem, ed, by O. C. Taylor, Task B Rep. part B, 1-12. Riverside, Air Pollution Research Center, University of California. LILLIE, R. J. (1970). Air pollutants affecting the pe([brmance of domestic animals. Washington, USDA agric. Handbk, 380. MARTIN, M. H. & COUGHTREV, P. J. (1975). Preliminary observations on the levels of cadmium in a contaminated environment. Chemosphere, 4, 155-60. MARTIN, M. H. & COUGHTREV, P. J. (1976). Comparison between levels of lead, zinc, and cadmium within a contaminated environment. Chemosphere, 5, 15-20. MIVAMOTO,Y. (1975). Kankyo osen no shihyo to siteno dobutsu kisetsu. Kansokuritsu kara mira nihon no osen bunpu. (Animal phenology as an indicator of environmental pollution: Distribution of environmental pollution in Japan seen from frequency of observation.) Tokyo Kanku Chiho Kisho Kenkyukai-shi (Geophys. Notes Tokyo Distr. Meteorol. Observ.), 8, 27-9. NEWMAN,J. R. (1975). Animal indicators of air pollution: A review and recommendations. Corvallis, Ore., U.S. Environmental Protection Agency, Corvallis Environmental Research Laboratory, Rep. CERL-006. NEWMAN, J. R. (1977). Sensitivity of the house martin (Delichon urbica) to fluoride emissions. Fluoride, 10, 73 6. NEWMAN, J. R. & NOV~,KOV~,, E. (1977). Effect of air pollution on nesting of the house martin (Delichon urbica). Unpublished manuscript, Gainesville, Florida, Environmental Science and Engineering, Inc. NEWMAN, J. R. & YU, M. (1976). Fluorosis in black-tailed deer. J. Wildl. Dis., 12, 39-41. NISHINO, O., ARARI, M., SENDA, I. & KUBOTO, K. (1973). Influence of environmental pollution of the sparrow. Jap. J. Publ. Hlth, 20, 1. NOV~,KOVA, E. (1969). Influence des pollution industrielles sur les communaut6s animales et l'utilization des animaux comme bioindicateurs. Proc. Eur. Congr. Influence Air Pollut., 1st, Wageningen 1968, 41-8. NOVAKOV~,, E. (1970). Influence of industrial air pollution on urine reaction in horses. Proc. int. Congr. Nutr., Prague, 1969, 8th, 712-16. NOVAKOVA,E., FINKOV/~,A. & SOVA,Z. (1973). Etude pr61iminaire des prot6ines sanguines chez le lievre commun expos6 aux pollution industrielles. Nemzetkdzi Vadaszati tudomanyos Konferencia Eldadtlsai I1. seki6, Apr6vadaszda Ikodas Sopron, Budapest 1971, 69-84. NovkKovk, E. & HANZL, R. (1967). Pfispevek k populacni dynamice zajice polniho (Lepus europaeus Pall.) Lynx, 8, 28-42.

190

JAMES R. NEWMAN

ROBINETTE,W. L., JONES,D. A., ROGERS,G. & GASHWILER,J. S. (1957). Notes on tooth development and wear for Rocky Mountain mule deer. J. Wildl. Mgmt, 21, 134-52. ROYAL COMMISSION(1878). Noxious vapours. London, HMSO, Royal Commission Rept, No. 614. RUBAY, M. (1932). About the fog observed in the Meuse Valley in December 1930 and its noxious effects on animals. Annls. Mid. v~t., 77, 145-58. SCHWABE, C. W. (1969). Veterinary medicine and human health. Baltimore, Williams and Wilkins Co. TENDRON(1964). Effects of air pollution on animals and plants. European Conference on Air Pollution, 24 June to 1 July 1964, Strasburg, Council o f Europe Rpt, 25-70. WEBSTER, I. (1963). Asbestosis in non-experimental animals in South Africa. Nature, Lond., 197, 506. WELLINGS,S. R. (1970). Respiratory damage due to atmospheric pollutants in the English sparrow, Passer domesticus. In Project clean air, Davis, Department of Pathology, University of California, Research Project S-25. WIEMAN (1939). Copper poisoning due to flue gases. Dr. Tieriirztl. Wschr., 47, 279-81. YONT, W. P. & SAYERS,R. R. (1927). Hydrogen sulfide as a laboratory and industrial poison. J. chem. Educ., 4, 613-19.