1. Respiratory symptoms of workers on large dairies in the San Joaquin Valley compared to control facility employees Presented by: Chelsea Eastman COEMH Training Workshop May 2010

2. Background: CA Dairy Industry $7.3 billion, milk & cream sales 21.9% US milk supply CA: 1,960 dairies  1.8 million lactating cows Northern CA: 1,788 dairies  1.7 million lactating cows Average herd size: 952 Source: California Department of Food & Agriculture, 2008

3. Background: Dairy Operations

4. Background: Dairy Workers CA dairy employees: 16,700  8% of agricultural workers SJV dairy employees: 12,700  15% of agricultural workers Source: CDFA, 2005

5. Background: Agricultural Work & Respiratory Health Chronic endotoxin exposure  chronic bronchitis  reduced lung function PM exposure  reduced lung function  airway inflammation Sources: Iversen et al, 1994; Omland, 2002; Reynolds et al, 1996

6. Background: Agricultural Work & Respiratory Health Dairy farmers at high risk  respiratory health problems  decreased lung function Animal confinement facilities  airway inflammation  organic dust toxic syndrome Sources: Kawada et al, 2008; Chaudemanche et al, 2003; Dalphin et al, 1998; Gainet et al, 2007; Heller et al, 1986; Malmberg, 1990; Venier et al, 2006

7. Study Design and Methods Cross-sectional  June through September 2008 Dairy selection  ≥ 1,000 milking cows  Randomly selected  ≤ 3 per county Inclusion criteria  18 - 65 years  Male  Able to work a fully monitored 6-hr shift  Able to perform spirometry  Work around cows

8. Study Design and Methods Control facility  Vegetable processing plant Selection criteria  Similar worker demographics as dairies  Night shift Inclusion criteria  18 – 65 years  Male  Able to work a fully monitored 6-hr shift  Able to perform spirometry  No work around cows  No respiratory exposures (i.e. cleaning chemicals)

9. Study Design and Methods 13 dairies  226 participants  90% participation Control: 1 vegetable processing plant  49 participants  90% participation

10. Study Design and Methods Pre-shift interview  Demographics  Asthma & atopy  Chronic respiratory conditions Post-shift interview  Time-activity log  Smoking/tobacco use  Health self-assessment

11. Hypothesis Dairy workers exhibit a higher prevalence of respiratory symptoms than a comparison group of workers independent of age, cigarette smoking, and non-occupational effect modifiers.

12. Results: Study Population Dairy WorkersControl Employees Mean (SD)MedianMean (SD)Median Age (Years)33.3 (11.1)31.034.8 (12.1)32.0 Years in USA*12.1 (9.0)10.08.9 (7.9)5.5 Dairy WorkersControl Employees Country of Originn%n% United States73.136.1 Mexico20188.94693.9 Other188.000.0 *p-value < 0.05

13. Results: Study Population Dairy WorkersControl Employees n%n% Two-Week Income † $0 - 75094.22040.8 $750 – 1,0009644.22142.9 $1,001 – 1,50010046.148.2 $1,500 +125.548.2 Education 6 th Grade or less12655.82040.8 7 th to 9 th Grade6629.21632.7 10 th Grade or more3415.01326.5 † p-value < 0.0001

14. Results: Study Population DairyControl Smoking Statusn%n% Current smokers6227.4714.3 Former smokers4419.51020.4 Never smokers12053.13265.3

15. Results: Chronic respiratory conditions Dairy n = 106 Control n = 17 n%n% Bronchitis21.900 Chronic cough21.900 Persistent wheeze21.900 Asthma*4340.6211.8 Hay fever1312.315.9 Eczema1312.315.9 Rhinitis2422.915.9 Dairy n = 120 Control n = 32 n%n% Bronchitis54.200 Chronic cough32.513.1 Persistent wheeze21.713.1 Asthma4436.7721.9 Hay fever1512.5516.1 Eczema86.7412.5 Rhinitis1613.3618.9 Current/former smokersNever smokers *p < 0.05

16. Results: Acute respiratory symptoms Dairy n = 62 Control n = 7 n%n% Eye irritation*23.2228.6 Blurred vision23.200 Nasal irritation23.2114.3 Throat irritation46.5114.3 Cough69.7114.3 Phlegm58.100 Tingling fingers0000 Rash0000 Wheeze0000 Chest tightness34.800 *p < 0.05 Current smokers Dairy n = 164 Control n = 42 n%n% Eye irritation95.549.5 Blurred vision53.112.4 Nasal irritation2112.812.4 Throat irritation2213.424.8 Cough2314.0716.7 Phlegm2515.224.8 Tingling fingers31.822.4 Rash31.800 Wheeze53.100 Chest tightness84.912.4 Former/never smokers

17. Key Points & Future Activities Dairy workers have a significantly higher prevalence of asthma symptoms than controls First project to study dairy workers in the Western United States Document if intervention is warranted Disseminate results to dairy community Design and target interventions to protect dairy worker respiratory health

18. Acknowledgments Dr. Marc Schenker Dr. Frank Mitloehner Dr. Debbie Bennett Dr. Diane Mitchell Cal-DEHRI Group WCAHS

19. THANK YOU