Maataloustieteellinen Aikakauskirja Vol. 59: 57—62, 1987 Gaseous health hazards in livestock confinement buildings JUHANI KANGAS, KYÖSTI LOUHELAINEN and KAJ HUSMAN Kuopio Regional Institute of Occupational Health, P.O. Box 93 SF-70701 KUOPIO (Finland) Abstract. Gas concentrations were measured on 16 farms (eight cattle farms, five piggeries, three poultry yards) mainly during wintertime. The gases were ammonia, carbon dioxide, methane, hydrogen sulfide, methyl mercaptan and other sulfides. The mean concentrations of ammonia varied between 8—43 cmVm3 in the air of live- stock building. In the poultry yards the mean concentration of ammonia was highest; it was lower in piggeries and especially in cow houses. Carbon dioxide concentrations were 500—3500 cmVm3 in cowhouses, 1000—4000 cm 3 /m3 in hoghouses and 600—4000 cmVm3 in poultryyards. Very low concentrations of methane and sulfur compounds were found in the livestock con- finement buildings. It is obvious that in normal working situations only ammonia of the measured gases ex- ceeds the threshold limit value (25 cmVm3 ). High ammonia concentrations can be expected in the floor type poultry confinement buildings especially when manure is left on the floor for several months. In such cases effective mechanical ventilation is the only way to keep the ammonia level acceptable. Index words: farmers’ gas exposure, ammonia, gases in livestock confinement buildings. Introduction Ammonia and hydrogen sulfide have been suspected to be an occupational health hazard for farm workers in livestock confinement buildings. These gases have been identi- fied among the main components of malodor- ous gases from swine and poultry manure (Spoelstra 1980). There is, however, little in- formation on occupational hygiene measure- ments of gas concentrations in different live- stock buildings. Ammonia, hydrogen sulfide, carbon diox- ide and carbon monoxide were measured in swine producing farms by Donham and others (Donham & Popendorf 1985). They found that ammonia most commonly exceeded the TLV (threshold limit value). According to their measurements other gases do not present an acute health hazard in normal situations. 57 JOURNAL OF AGRICULTURAL SCIENCE IN FINLAND https://www.c-info.fi/en/info/?token=fzWHcIu_DIlnPVlO.QU1fPwh1M62v6hcTpCOu5g.F3s7vKGnnusGkHH5XEz_U3VaMTZpGWnauyh_AjhqpS0Smj5eV4LYXanLzTAb8N-gFGMQ9BEM9bE_Mk5fHXtlMmrGy2uoX6lQkhBpe95s6q_OLrNWfDvVL3mAl9hTxJ2fmClHvHeKZIXp9RRvEd2qpfjmCt-IsLnJkmMhlJT5D5JdhYL8uZns8MXekMnc3Xe-14nVVjEglJdJ1u2NcpFyws0WkQ In the work of Batel (Batel 1975), ammonia was found to reach higher concentrations in piggeries than in cow houses. Ammonia con- centrations were I —3o cmVm3 in normal barn farms and o—l20—12 cmVm3 in loose barn farms in Finland and the mean concentrations of dif- ferent farms were 4—9 cmVm3 and I—91 —9 cmVm3 respectively (Anon 1975, Karhunen et al. 1979). Jones et al. found ammonia levels of about 25 cmVm3 in active work areas of poultry con- finement buildings, but the levels could be much higher in areas with poor ventilation (Jones et al. 1984). In a turkey house ammonia was found to be between 40—50 cmVm3 , when the ventila- tion functions properly (Aschbacher 1973). In a normal work situation, the concentration of hydrogen sulfide is low, but may rapidly reach toxic levels if manure is agitated (Don- ham et al. 1977, Donham et al. 1982, Osborn & Crapo 1981) or the ventilation is off (Aschbacher 1973). The objective of this study was to measure concentrations of ammonia, methane, carbon dioxide and sulfur compounds in Finnish livestock confinement buildings. Materials and methods Concentrations of gases were measured on 16farms (8 dairy cattle houses, 5 piggeries and 3 poultry yards) mainly during wintertime. In one piggery and in three poultry yards am- monia was measured also during summer. Three of the piggeries had fattening pigs and two had both fattening pigs and sows. Two of the poultry houses were coop type units and one was a floor poultry yard. Seven livestock confinement buildings had mechanical venti- lation with an exhaust volume of 800 to 8500 mVh during measurements. In farms with natural ventilation, the exhaust air volume varied from 900 to 2300 m 3/h during measure- ments. The outdoor temperature varied during measurements from + 2°C to —2O°C in win- ter, and from +lo° to +2O°C in summer. With the exception of carbon dioxide, the gases were measured mainly by stationary sampling method with sampling time from 0.5 h to 2 hours. Ammonia samples were collected into im- pinger flasks containing 10 ml of 0.1 M sul- furic acid. Ammonium ion was detected with an ion selective electrode (Orion Research). The detection limit was 0.01 cmVm3 . Methane samples were collected in 41 laminated plastic bags and analyzed with a gas chromatograph (Hewlett Packard 5370A) equipped with a flame ionization detector. The column was packed with Carbowax 20M, with pure nitro- gen (40 ml/min) as the carrier gas and column temperature 60°C. The detection limit for methane was 1.0 cmVm3 . Hydrogen sulfide was collected into im- pinger flasks containing 30 ml of 0.02 M CdS04 solution. Collected hydrogen sulfide was determined by methylene blue method (Jacobs, 1967). The detection limit for hy- drogen sulfide was 0.01 cmVm3 . On each farm, air samples were collected into a 4 1 plastic laminated bag in order to analyze the concentration of the principal sul- fur compounds. The stability of samples in plastic laminated bags has been tested earlier (Kangas et ai. 1986). The samples in the bags were injected into a gas chromatograph (Analytical Instruments Development, Model 621 —l9) equipped with a flame photometric detector. A Teflon column was used packed with Chromosorb T 60/80 coated with a mixture of polyphenyl- ether and orthophosphoric acid. The oven temperature was 60°C, and an optimum flame in the detector was achieved by purging with hydrogen (55 1/min) and air (85 1/min).Pure nitrogen served as the carried gas (20 1/min). This procedure yielded a good separation of the principal sulfur compounds with detection limits for hydrogen sulfide at 0.005 cmVm3 , for methyl mercaptan at 0.005 cmVm3 , for dimethyl sulfide at 0.03 cmVm3 and for dimethyl disulfide at 0.05 cmVm3 . Standards were prepared by permeation tube technique. The permeation rates of the 58 standard gases are dependent on the ambient temperature. The permeation tube is placed in a thermostatic chamber and thepermeated gas is diluted with nitrogen. By altering the carrier gas flow and temperature, the standard gas concentrations can be changed. Carbon dioxide was determined by Draeger indicator tubes with Draeger hand pump (Drä- gerwerk AG Liibeck). Results With one exception, the ammonia concen- trations in cow houses were below the TLV (25 cmVm3). In piggeries and especially in poultry yards, the ammonia concentrations occasionally reached very high levels (Table 1). In one piggery and in three poultry yards ammonia levels were measured during both winterand summer. During summer the con- centration of ammonia was three times high- er than in wintertime. In poultry yards the am- monia level in ambient air was lower in sum- mer than in winter. The exposure of farmers to hydrogen sul- fide on Finnish farms was found to be mini- mal normal working situations (Table 2). When manure was agitated, hydrogen sulfide was liberated and concentrations rising to 27 cmVm3 were measured. Organic sulfur com- pounds (methyl mercaptan, dimethyl sulfide and dimethyl disulfide) in ambient air remain- ed under the respective detection limit of the method used for analysis. Methane concen- trations were highest on cattle farms, 35—290 cmVm3 and lower in piggeries and poultry yards (Table 2). The concentration of carbon Table 1. Ammonia concentrations in cow houses, pig- geries and poultry yards, cmVm1 . cow piggeries poultry yards houses ; ; winter summer winter summer winter mean 7.8 17.8 35.8 38.0 43.0 SD 6.6 11.2 16.0 33.0 13.0 min 0.2 4.7 16.4 3.0 23.7 max 35.0 34.6 57.4 138 67.2 N 50 42 4 33 8 Table 2. Concentrations of hydrogen sulfide (H2S), methane (CH 4 ) and carbon dioxide (CO 2) in cow houses, piggeries and poultry yards, cmVm 3 . cow piggeries poultry houses yards mean 0.4 0.02 0.5 SD 0.8 0.01 0.3 H2 S min 0.01 0.01 0.3 max 2.9 0.02 1.2 N 11 10 5 mean 170 12 3 SD 75 9 CH4 min 35 5 3 max 290 30 3 N 8 6 3 mean 1520 2000 1900 SD 850 920 910 C02 min 500 1000 600 max 3500 4000 4000 dioxide was similiar in different types of build- ings and all results were below the TLV (5000 cmVm3) (Table 2). Discussion Ammonia is formed through the hydrolysis of urea (Spoelstra 1980). Our results con- firm earlier findings that ammonia is the most abundant gas in active areas of the livestock confinement buildings when compared to their threshold limit values. Especially in floor poultry yards high ammonia concentrations were measured during wintertime (maximum 138 cmVm3 ). The reasons for these high am- monia levels were that manure is kept on the floor for several months during wintertime and there was no mechanical ventilation in these poultry yards, and the inlet ducts were tightly closed in order to maintain the air tem- perature comfortable for the hens. Mechanical ventilation is needed to lower the ammonia concentration in poultry yards. This was noted during the summer when lower concentrations of ammonia were measured while doors and windows were kept open, even though the microbial hydrolysis of urea into ammonia is more active during the warm 59 season. The influence of the outdoor tem- perature on the hydrolysis of urea was seen in the results of ammonia measurements in piggeries with mechanical ventilation. In win- tertime the concentration of ammonia was lower than in summer. The difference in the ammonia concentrations between the floor and coop type poultry yards noted during win- tertime was not noted in summer. This was probably due to the more effective natural ventilation in summer. The high level of ammonia in poultry con- finement buildings might be lowered by using some gas absorbing material such as a litter; for example peat could be effective for this purpose. The observed concentrations of am- monia in the poultry confinement buildings are so high that irritation of the eyes and mucous membranes are expected among the exposed farmers. According to our earlier measurements the piggeries and poultry yards were very dusty workplaces (Louhelainen et al. in press). Ammonia may also adsorb to the dust particles, and by this way reach high local concentrations at the deposition areas of the farmers’ lungs. This might partly explain the observed high prevalence of chronic bron- chitis among Finnish farmers (Terho et ai. in press). Methane reached highest concentrations in the dairy houses (35 —290 cmVm3 ). In pig- geries and in poultry confinement buildings we measured clearly lower levels. In the nearly anaerobic conditions of cow rumen carbohy- drate is fermented almost entire by into fatty acids and methane. This is most probably the main source of methane in cow houses (Kay 1983). In general, methane is the final product of microbial degradation of organic material. Methane in poultry yards and piggeries origi- nates from this source (Stevens & Cornforth 1974). However, methane concentrations are at such a low level that they do not provide an occupational health or safety hazard to the farmers in their active working areas. Sulfur compounds are formed from the microbial degradation of sulfate-containing material in the manure. Sulfate-reducing bac- teria produce mainly hydrogen sulfide but also other malodorous sulfur gases (mercaptans) can be found as a result of reduction of sul- fur compounds in wastes (Hatchikian 1976). We detected only hydrogen sulfide in the live- stock confinement buildings and the concen- tration was low. We can conclude that during normal working situations (no agitation of the manure) there is no risk of excessive hydro- gen sulfide exposure on the Finnish farms. The situation is quite different when the con- tainer of the liquid manure is pumped dry and the farmer has to work near the pit or the slur- ry tank (Donham et al. 1977, Donham et al. 1982, Osborn & Crapo 1981). Carbon dioxide is one of the main com- ponents of the breathing gases of the animals but it is also formed by microbial degradation of carbonaceous material (Stevens & Corn- forth 1974). The level of carbon dioxide re- mainedbelow TLV in all measurements. It has often been mentioned to be an indicator of in- door air quality. According to our measure- ments, there was no correlation between car- bon dioxide and ammonia or methane. How- ever, this would need further investigation focusing mainly on the correlation between the carbon dioxiode concentration and the ventilation in the livestock building. We believe that the concentration of carbon dioxide could be a rough indicator of the ef- ficiency of ventilation in livestock confine- ment buildings. References Anon, 1975. Parsinavettatutkimus 1973—75. Vakolan livestock production systems. J. Air. Poll. Cont. Ass. tiedote 24/75, Vakola, Helsinki. 23: 267—272. Aschbacher, P.W. 1973. Air pollution research needs: Batel, W. 1975. Messungen zur Staub-, und Geruschs- 60 belastung an Arbeitsplätzen in der Landvirtschaflichen Produktion und Wege zur Entlastung Ertster Bericht. Grundlagen Landlechnik Bd 25: 135—157. Donham, K.J. & Popendorf, W.J. 1985. Ambient levels of selected gases inside swine confinement buildings. Am. Ind. Hyg. Assoc. J. 46: 658—661. Donham, K.J., Knapp, L.W., Monson, B.S. & Gustaf- son, K. 1982. Acute toxic exposure to gases from liquid manure. J. Occup. Health. 24: 142—145. Donham, K.J., Rubins, M., Thedell, T.D., Kannermeyer, J. 1977. Potential health hazards to agricultural workers in swine confinement buildings. J. Occup. Med. 19: 383—387. Hatchikian, E.C., Chaigneau, M. and LeGall J. 1976. Analysis of gas production by growing cultures of three species of sulfate-reducingbacteria. In: H.G. Schlegel, G. Gottschalk and N. Pfennig (Eds.), Microbial Pro- duction and Utilization of Gases. E. Goltze, K.G. Got- tingen, 109—118. Jacobs, M.B. 1967. The analytical toxicology of indus- trial inorganic poisons pp. 545—548. Interscience Publishers John Wiley & Sons, New York (Sydney) London. Jones, W., Morring, K., Olenchock, S.A. Williams, T. & Hickey, J. 1984. Environmental study of poultry confinement buildings. Am. Ind. Hyg. Assoc. J. 45: 760—766. Kangas, J., Nevalainen, A., Manninen, A. and Savolai- nen, H. 1986. Ammonia, hydrogen sulphide and meth- yl mercaptides in Finnish municipal sewage plants and pumping stations. The Sci Total Environ. 57: 49 —55. Karhunen, J., Pyykkönen, M., Mykkänen, U., Niemi- nen, L. and Saloniemi, H. Pihattotutkimus 1976—78. Vakolan tiedote 29/79. Vakola, Helsinki 1979. Kay, R.N.B. Rumen function and physiology. The Vet Rec July 2, 1983, 6—9. Louhelainen, K., Kangas, K., Husman, K. & Terho, E.0.: Total concentrations of dust in the air during farm work: In: Terho E.0., Husman, K. & Vohlonen, I. (eds.) Work related respiratory diseases among Finnish farmers. Eur. J. Resp. Dis. Suppl. in press. Osborn, L.M., Crapo, R.O. 1981. Dung Lung: a report of toxic exposure to liquid manure. Ann. Inter. Med. 95; 312—314. Spoelstra, S.F. 1980. Origin of objectionable odorous components in piggery wastes and the possibility of ap- plying indicator components for studying odour devel- opment. Agric. Environ. 5: 241—260. Stevens, R.J. and Cornforth, I.S. 1974. The effect of aeration and gases produced by slurry during storage. J. Sci Food Agric 25: 1249—1261. Terho, E.0., Husman, K. & Vohlonen, I.: Prevalence and incidence of chronic bronchitis and farmer’s lung with respect to age, sex, atopy and smoking. In: Terho E.0., Husman K. & Vohlonen, I. (Eds.) Work-related respiratory diseases among Finnish farmers. Eur. J. Resp. Dis. Suppl. In press. Ms received March 2, 1987 SELOSTUS Kaasumaiset ilman epäpuhtaudet tuotantorakennuksissa Juhani Kangas, Kyösti Louhelainen, Kaj Husman Kuopion aluetyöterveyslaitos, PL 93, 70701 Kuopio Tutkimuksessa mitattiin ilman kaasupitoisuuksia 16 maatilalla (kahdeksan navettaa, viisi sikalaa jakolme ka- nalaa) pääasiassa talviaikaan. Kaasut olivat ammoniak- ki, hiilidioksidi, metaani, rikkivety, metyylimerkaptaani ja sulfidit. Työsuojeluhallituksen antamat 8 tunnin HTP-arvot (haitalliseksi tunnetut pitoisuudet) eri kaasuille ovat: am- moniakki 25 cmVm’, rikkivety 10 cmVm', metyylimer- kaptaani 0,5 cmVm J jahiilidoksidi 5000 cmVm1 . Metaa- nille ja muille rikkiyhdisteille tällaisia arvoja ei ole. Keskimääräiset ammoniakkipitoisuudet olivat navetois- sa 7,8 cmVm 1 (vaihtelu 0,2—35 cmVm'), sikaloissa 17,8 cmVm 1 (4,7 —34,6 cmVm 1) ja kanaloissa 38,0 cmVm 1 (3,0 —138 cmVm! ) talvella. Kesällä tehdyissä mittauksissa yhdessä sikalassa ammoniakkia oli keskimäärin 35,8 cmVm' (16,4—57,4 cmVm1 ) jakolmessa kanalassa 43,0 cmVm J (23,7—67,2 cmVm!). Rikkivetypitoisuudet olivat alhaiset kaikissa tuotanto- rakennuksissa normaalin työn aikana. Sekoitettaessa lie- telantaa lantakourussa rikkivetypitoisuus nousi 27 61 cmVm3 . Muiden rikkiyhdisteiden (metyylimerkaptaani, dimetyylisulfidi ja dimetyylidisulfidi) olivat alle analyy- silaitteen määritysrajan (alle 0,05 cmVm3). Metaanipitoi- suudet olivat alhaiset ja niiden työhygieeninen merkitys vähäinen. Hiilidioksidipitoisuudet olivat navetoissa 500—3500 cmVm 1 ja kanaloissacmVm3 , sikaloissa 600—4000 cmVm1 . 1000—4000 Tutkimustulosten mukaan ammoniakki on mitatuista kaasuista haitallisin kotieläinrakennuksissa. Suurimmat pitoisuudet (maksimi 138 cmVm 1) mitattiin lattiakana- loissa talvella. Syinä korkeaan ammoniakkipitoisuuteen ovat mm. lattialla oleva lanta ja vähäinen ilmanvaihto- määrä. Muiden kaasujen pitoisuudet olivat alle HTP- arvojen. 62