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

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

Background: Dairy Operations

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

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

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

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

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)

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

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

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.

Results: Study Population Dairy WorkersControl Employees Mean (SD)MedianMean (SD)Median Age (Years)33.3 (11.1) (12.1)32.0 Years in USA*12.1 (9.0) (7.9)5.5 Dairy WorkersControl Employees Country of Originn%n% United States Mexico Other *p-value < 0.05

Results: Study Population Dairy WorkersControl Employees n%n% Two-Week Income † $ $750 – 1, $1,001 – 1, $1, Education 6 th Grade or less th to 9 th Grade th Grade or more † p-value <

Results: Study Population DairyControl Smoking Statusn%n% Current smokers Former smokers Never smokers

Results: Chronic respiratory conditions Dairy n = 106 Control n = 17 n%n% Bronchitis Chronic cough Persistent wheeze Asthma* Hay fever Eczema Rhinitis Dairy n = 120 Control n = 32 n%n% Bronchitis Chronic cough Persistent wheeze Asthma Hay fever Eczema Rhinitis Current/former smokersNever smokers *p < 0.05

Results: Acute respiratory symptoms Dairy n = 62 Control n = 7 n%n% Eye irritation* Blurred vision Nasal irritation Throat irritation Cough Phlegm Tingling fingers0000 Rash0000 Wheeze0000 Chest tightness *p < 0.05 Current smokers Dairy n = 164 Control n = 42 n%n% Eye irritation Blurred vision Nasal irritation Throat irritation Cough Phlegm Tingling fingers Rash Wheeze Chest tightness Former/never smokers

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

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

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