An Overview of Agricultural Medicine

1. An Overview of Agricultural Medicine Tisha Titus, MD, MPH Slides provided by: Michael B Miller, DO, OD, MPH Chief, Occupational Health Services Atlanta VAMC

3. Agricultural Medicine 1713- Bernardino Ramazzini, father of occupational medicine Farmers “wrestle with unending toil and the direst poverty…” Despite improvements in production methods, agriculture remains one of the top three hazardous occupations along with mining and construction

4. AgroMedicine WHO- by 2020, injuries will be responsible for more deaths, morbidity, and disability than any other diseases Worldwide, 2007, injuries account for 1 in 7 of potential life-years lost By 2020, 1 in 5 potential life years lost due to injuries Agricultural related injuries now recognized as a serious public health problem, especially in developing nations

5. AgroMedicine “Agriculture accounts for 70 per cent of child labor worldwide” 2006 - 150 million children under age 18 in agriculture (Food and Agriculture Organization, UN)

6. Outside of North America and Europe, information about agricultural injuries is scant - injury control efforts are well below the level of those directed at other health problems US- occupational injury control efforts include enactment of OSHA in 1970 Since then, specific efforts directed to agricultural injuries and illnesses- NIOSH directed to develop extensive ag safety and health program to address high risks of injuries and illnesses by workers and families in agriculture

7. Agricultural medicine In US - population at risk = 2+ million farm workers 50% of ag workers are migrant workers 700,000 under age 20 live and work on farms Additional 300,000 under age 20 hired to work on farms

8. AgroMedicine 120,000 work-related disabling injuries per year 500-700 fatalities per year 100/year - children are killed on farms 22,648 ag-related injuries occurred in children/adolescents under age 20 (2001) Higher fatality rates than other industries (26/100,000 vs 4/100,000 all industries combined)

9. AgroMedicine “There is no single, continuous source of non-fatal agricultural injury data.” (National Ag Safety Database)

10. AgroMedicine The cost of ag injuries in US are significant in sharp contrast to the attention that they receive in discussions of health care costs, or even injuries in general Despite efforts, ag injuries estimated at $4.855 billion (2001) and on par with the costs of other job-related health problems

11. Physical Agents

13. Excessive Noise • Hearing loss demonstrated in farmers in their twenties • Pattern of hearing loss • 4000-6000 Hz initially effected – extends to higher and lower frequencies • Usually greater in left ear • Farmers commonly exposed to noise levels over 90 dB

14. Long term Exposure to Segmental Vibration • Raynaud’s phenomenon, muscle tightening, & paresthesia • Sensory & motor nerve damage • Fingertip necrosis • Bone decalcification and cysts

15. Injuries from heat and cold • Heat exposure from weather – heat stroke or cramps • Injuries from hot equipment • Cold exposure from weather or items like super cold anhydrous ammonia – frost bite

16. Prevention of injuries from heat and cold • Appropriate clothing • Adequate water and rest in hot weather • Air conditioned tractors for hot weather • Appropriate use of safety equipment and precautions

18. Lungs and airway disease Farmers are exposed to various dusts, particulates, irritant gasses and mold spores which cause acute or chronic airway and lung problems

19. Lungs and airway disease Upper respiratory infections are at least two times more common among migrant workers. This is especially a problem in children.

20. Farmer’s lung presentation • A recurrent acute pneumonia with fever, dyspnea, cough and malaise • Often asymptomatic • Often presents as recurrent, febrile URI’s • Continual or repeated exposures – chronic disease with fibrosis

21. Farmer’s lung pathophysiology • Combined type III and IV immune response • Primary sensitization to inhaled antigens over 6-10 weeks • Symptoms 4-6 hours after minimal exposure – subside in hours to several days

22. Farmer’s lung treatment and prevention • Prevention of re-exposure to antigen is most important • Cromolyn sulfate may be prophylactic and prevent delayed onset of symptoms • High dose corticosteroids in acute disease • Early recognition – apparent decrease in disabling, chronic cases

23. ODTS presentation • A flu-like illness with fever, dyspnea, cough and leukocytosis • Less severe than farmer’s lung • More common than farmer’s lung • Often misdiagnosed as farmer’s lung

24. ODTS pathophysiology • Precipitating antibodies to thermophilic actinomycetes • Endotoxins may cause the disease • Occurs after a delay after high-level dust exposures • All exposed individuals affected, proportional to exposure – thus, cases appear in clusters

27. SFD presentation • Initial airway inflammation, pneumonia, and pulmonary edema • Present with dyspnea, cough, chest pain, cyanosis, nausea and vomiting • Extensive bronchiolitis obliterans after 10-31 days

28. SFD pathophysiology • Microbes ferment contents of just filled silos and turn nitrates into nitrogen dioxide and tetroxide • Once inhaled, combine with water – generate nitrous and nitric acids • Airway inflammation, pneumonia, and pulmonary edema • Several hours delay between exposure and symptom onset • High levels rapidly cause death

29. SFD Treatment and prevention • Stay out of silos until 3rd day after filling • If you must enter: • Blower for 30 minutes • Respirator and safety lines and harness • Start corticosteroids immediately and continue for at least 8 weeks

31. Livestock confinement buildings • Infectious agents, dust and gasses concentrate • Swine confinement buildings appear worst • Dust contents in swine confinement buildings • Dust heavier when animals handled or moved and in winter • Irritant, toxic and asphyxiant gasses from animal waste breakdown

32. Livestock confinement buildings • Health effects • Short-term health effects • Flu-like illness after 4-6 hours delay • Long-term health effects • Hydrogen sulfide effects • Ammonia effects

34. Livestock confinement buildings • Prevention and reduction of exposures • Engineering and management controls • Personal protective equipment

35. Grain dust • Contain a large mixture of substances • Long known to affect the lungs, eyes, and throat – may cause conjunctivitis and rhinitis • Most widespread effect is chronic bronchitis – up to 75% of grain workers affected

36. Grain fever presentation • A flu-like disease • Initially, cough, dyspnea, chest tightness, substernal burning pain and headache • After several hours, fevers, chills, myalgia and malaise • May occur during or shortly after high level exposure • Symptoms typically diminish after several hours – can continue for days

37. Grain fever – possible mechanisms • Type III immune reaction to grain fungi • A host reaction to endotoxins • Grain dust components releasing non-allergic mediators

38. Asthma • Mold spores • Fungal growth in grain and hay • Poultry antigens • Animal dander • Grain dust • Pollen from cereal grains

39. Other chemicals • Nitrates and nitrites • Methemoglobinemia in infants • Conversion to nitrosamines – possible carcinogen risk • Also, gasoline, solvents, and welding fumes • Pesticides • Developmental, endocrine and reproductive effects

40. Pesticides • Organophosphates • Carbamates • Organochlorines • Pyrethroids • Biopesticides • Acute Toxicity: • Headache • Hypersecretion • Muscle twitches • Nausea • Diarrhea • Resp depression Chronic pesticide exposure leads to increased risk of several cancers & neurodegenerative Dz

42. Causes of agricultural injuries • Most caused by machinery with moving parts • Farm animals second most common cause • Electrical power lines • Falls from height

43. Common causes of agricultural injuries • Grain augers • Tractors • Most common cause of child mortality on farms • Clothing tangled in PTO shaft • Rollovers • Run overs • All-terrain vehicles • Hay balers

45. Common causes of agricultural injuries • Swathers • Combine harvesters • Front-end loaders • Farm animals • Objects containing electrical power lines • Falls from heights • Lawn mowers

48. Musculoskeletal problems • Elevated prevalence of osteoarthritis and rheumatism • Degenerative knee disease in dairy farmers • Back pain

49. Cancer • Overall cancer rate lower for farmers • Sunlight-ultraviolet radiation may cause skin and lip cancers • Sunscreen and clothing protective • Also, excesses of leukemia, lymphoma, and cancers of connective tissue, brain, and prostate

50. Dermatitis • Dermatitis risk highest among crop producers • Major causes • Agricultural chemicals • Animal and plant products