Dr. Renée Anthony - Hazards and Prevention of Airborne Exposures and Risks

T. Renée Anthony, PhD, CIH, CSP

Department of Occupational and Environmental HealthThe University of Iowa

[email protected]

Pit Foam & Producer Safety:Hazards and Prevention of Airborne Exposures and Risks

Iowa Pork CongressJanuary 27, 2016 | 10:45 – 12:00Hy-Vee Hall, Lower Level, Rooms 107 & 108

Seminar Objective Dr. Renée Anthony

Identify chronic and acute health and safety hazards associated with chemicals in swine production buildings

Discuss identification and prevention alternatives

Leon Sheets Share producer experiences of barn fire

Dr. Dan Andersen Update state of knowledge of foaming manure Discuss prevention strategies

Objectives Provide Motivation and Rationale Identify chronic health hazards in swine production

buildings Common contaminants Health risks: current state of knowledge Prevention options

Discuss acutely hazardous gases: H2S and CH4 Sources Risk factors Prevention considerations

Acknowledgements Great Plains Center for Agricultural Health

CDC/NIOSH U54 OH007548

Iowa Fatality Assessment and Control Evaluation (FACE) CDC/NIOSH 2U60OH008460-10 Subcontract with the Iowa Department of Public Health

(IDPH)

I: Chronic Health Hazards Air contaminants in swine CAFO

Ammonia (NH3) – manure pits, urine Hydrogen sulfide (H2S) – manure pits Dust (respirable, inhalable) – food, animal dander, manure Endotoxin (on dust) – animal dander, manure Carbon monoxide (CO) – heaters Carbon dioxide (CO2) – heaters, swine respiration

Workers in swine CAFO exhibit adverse health outcomes Declines in lung function (FEV1 dose-dependent) Increased prevalence of respiratory symptoms

(chronic cough, phlegm) Increased prevalence and amount of inflammation

(bronchial lavage)

Clear need to reduce exposures to these workers

Risk Factors Clear need to reduce exposures to these workers

Winter exposures are highest



O'Shaughnessy et al. (2010) A Task-specific assessment of swine worker exposure to airborne dust. Journal of Occupational and Environmental Hygiene 7(1):7-13

Inhalable Dust Endotoxin



Duchaine et al. (2000) Influence of building maintenance, environmental factors, and seasons on airborne contaminants of swine confinement buildings. AIHAJ 61(1):56-63

“Total” Dust Endotoxin Ammonia

Dust and ammonia significantly higher in winter.(Endotoxins analyzed by different methods: not comparable between seasons)



Jacobson et al. (2005) Spatial, diurnal, and seasonal variations in temperature, ammonia, and hydrogen sulfide concentrations in two tunnel ventilated sow gestation buildings in MN. Livestock Environment VII, Proceeding of 7th International Symposium 18-20 May 2005, ASAE Publication 701P0205, 198-206

Hydrogen Sulfide (Gestation)

Ammonia(Breeding)

Significant increases in winter: 100 to 1000 ppb H2S, 2-25 ppm NH3


Winter exposures are highest Concentrations increase over the winter


Winter exposures are highest Concentrations increase over the winter


Winter exposures are highest Concentrations increase over the winter Exposure recommendations:

Single component – OSHA, ACGIH, other… not consider combined effect to compounds associated with health outcomes

Multiple component – Literature recommendations to prevent declines in lung function and inflammation

Recommended Exposure LimitsOccupational Exposure Limits (OELs) ACGIH TLVs – Single component limits, which do not account for mixtures

Threshold

Large Dust, mg/m3

Small (Respirable) Dust, mg/m3

NH3, ppm

CO, ppm

CO2, ppm

OEL 10 3 25 25 500050% OEL 5 1.5 12.5 12.5 250010% OEL 1 0.3 2.5 2.5 500Literature recommendations:

Donham et al. 1989, 1995

2.8 (T)(<10%

decrease in FEV1)

0.237

(3% decline in FEV1)

-1540(FEV50, FEF50)

Vogelzang et al. 2000 2.6 (I) 7.2

Increased bronchial hyperresponsiveness

Methods to Reduce Exposures Focus on dust/endotoxin exposure reduction Respiratory Protection: N95 Respirators

Low Adoption: 26% of MN farmers “sometimes” used (Odu et al. 2015)

Iowa Outreach: Community college education activities (fit testing, hands-on demonstrations) – Sheridan, Rudolphi

Engineering Controls Oil mist – Zhang et al. 1996; Senthilselvan et al.

1997; Rule et al. 2005 Recirculating ventilation with dust removal

(winter) – Park et al. 2013; Anthony et al. 2014, 2015; Peters et al. 2015

Methods to Reduce Exposures Recirculating Ventilation Findings

1000 cfm (5.4 air exchanges/hour) No increased room concentrations of gases

from operation (NH3, H2S, CO, CO2) Two air control units tested in farrowing barn

Filtration (SDC) reduced particles by: 33% for large (inhalable) 41% for small (respirable)

Cyclone reduced particles by: 44% for large (inhalable) 18% for small (respirable) Filtration (SDC) Cyclone

Methods to Reduce Exposures Recirculating Ventilation Findings

Also identified high CO2 generated by common LPG heaters Unvented heater (Yr 1)

Mean: 2480 ppm (330 ppm SD)Exceeded 1540 ppm all daysMean approached ½ single gas OELs

Vented heater (Yr 2)Mean: 1401 ppm (330 ppm SD)Exceeded 1540 ppm on 5 of 19 days

800 ppm drop due to heater Between years, outdoor temperatures

and sow/piglet counts also varied

Additional Information Detailed results of heater and ventilation studies

available http://www.public-health.uiowa.edu/gpcah/center-projects/in

tervention-to-reduce-exposures-in-cafos/

Ventilation Study:

http://www.public-health.uiowa.edu/gpcah/center-projects/intervention-to-reduce-exposures-in-cafos/



II: Acute Effects - Manure Gases High concentrations for short periods of time result in

serious health and safety hazards Hydrogen Sulfide (H2S) – In manure pit

50 – 100 ppm: altered breathing 100-300 ppm: pulmonary edema 500-700 ppm: collapse in 5 min, death 30-60 min 1000 ppm: nearly instant death “Heavier than air”

Methane (CH4) – In foaming manure Simple asphyxiant: every 4% increase in methane, 1%

decrease of oxygen Flammable at 5 to 15% (50,000 to 150,000 ppm) Foam: 50-70% Methane (too high to be flammable) When foam breaks: concentration dilutes and becomes

explosive “Lighter than air”

Fact Sheets:

H2S Fatalities (2015)

“Quick” attempt to retrieve equipment from pit resulted in two father-son fatalities in summer 2015

Iowa FACE report 2005 IA 024/025

Preventing Manure Gas Fatalities

Educate/warn: post signs Prevent accidental entries Don’t enter during / just after agitation Ventilate spaces prior to entry Enter only with adequate equipment

Retrieval system (harness, mechanical lift) Standby-by person SCBA Monitor With

Alarm

Foaming Manure Methane (CH4) is trapped in the foam but is

released when foam breaks Sources of breaking foam:

Dropped feed Manure agitation Pressure washing

Methane dilutes to flammable concentrations Sources of combustion:

Electric motors (e.g., pressure washers, feed systems) Pilot lights Welding/cutting Faulty/damaged wiring Smoking

Critical to eliminate combustion sources during activities when foam might break

Preventing Manure Gas Fatalities:Monitors

At-Risk decisions “I don’t have an SCBA, but I only need to go in for a

second.” “I can hold my breath” “I have had the fan on long enough…” “I pumped days ago…”

How can we tell if hazardous gases are at dangerous concentrations? Monitors can provide risk information to producer in real

time Prices are extremely low (single gas H2S ~$100) These units are commonly used in other industries

in high-hazard environments

Preventing Manure Gas Fatalities:How to Select Monitors

Currently:•No information on how long these last when stored in AG environments• Selections based on

purchase cost and warranty• Store in clean environment

•No “industry recommendations” for calibration and sensor (“bump”) check• Bump check before every

use• Calibrate at least monthly

and immediately before planned entries

Preventing Manure Gas Fatalities:Operating Monitors

Prepare to Sample Air for Manure Gases• Ventilate space• Allow sufficient warm-up time• Understand how long it takes your sensor to respond

– May take up to 90 seconds• Obtain tools to measure at a distance:

– 4 feet in front of you in the direction of travel– Mount monitor securely on stick or use probe with extension hose

• Confirm monitor is working:– Bump-test with gas to make sure it alarms– Calibrate per manufacturer’s instructions

• Identify alarm settings: – Be clear what you need to do if monitors alarm


Testing Order and Key Decisions:

1. Oxygen%LEL won’t give reliable numbers if insufficient O2

Need 21% O2

If lower, may have high methane:

Get out!

2. %LEL (flammable methane)

Need <1% LEL

10% LEL or more: Get out!

3. H2S

>10 ppm: Chronic health effects100 ppm: Get out!

The LEL of methane = 5% = 50,000 ppmA reading of “1%LEL” 500 ppm methane


To Test Prior to Entering Manure Pit

Test manure pit while outside of it first

Do not enter!Ventilate space then retest from

outsideSafe?

Test at entry location and every 4 feet (in front, to side, above, below)

No

Yes

Notes:

• Monitors take time to get true concentrations (60 -90 sec).

• We set alarms lower than what can cause death.• Concentrations can go up quickly, so react to low

concentrations as indication of inadequate ventilation.


To Test for Methane Gas in Barn

Washing Barn

1. Prohibit entry2. Prepare ventilation equipment and

monitor3. Implement shut-down for electricity and

gas4.Put monitor on worker during

activity:EVACUATE if %LEL Changes from 0%

5. If evacuate– Continue ventilating room– Return with a monitor, testing in 4 foot

increments, including ceiling level; back out if concentrations still high

– Return to task only when %LEL = 06. When work is completed/foam not at

risk of breaking, continue ventilating until confirm no methane

Hot WorkChanges to feed system

1. Prohibit hot work in barn with foaming manure

2. If work must be done, prevent activities breaking foam

3. Follow all procedures to the left

Pumping Manure Pit

1. Prohibit agitation when less than 2 feet between foam and slats

2. Ensure pit fans are operating

3. Follow all procedures to the left

4.If anyone enters barn, O2, H2S and %LEL monitors should be used

5. Continue ventilating barn after pumping back to background: 21% O2, <1 ppm H2S, 0% LEL

Summary Multiple compounds in the barn are associated with long-term adverse

health effects Respirators or improved ventilation, particularly during winter, can reduce

health risks

Acute hazards from manure gases still pose dangers Procedures via ASABE and Extension recommend ventilation duration and

safety protocols Available inexpensive technology can ensure concentrations throughout

the room are safe for activities• Working with monitors to recommend maintenance and lifetime to

recommend specifics• Developing training

Booth 1210 contains specifics Sign-up sheet for those interested in

classes on using monitors

Questions?Example monitors on display at Booth 1210

[email protected]

Fact Sheets: Ventilation Study:

QR code for gpcah web for farmers

Chronic Health Outcomes

AuthorsDeclines in Lung Function

Increased Respiratory Symptoms

Increased Airway Inflammation

Zuskin (1992) – Netherlands (N=59)

Cross-shift (FVC, FEV1, FEF50, FEF25)Lower pre-shift capacity vs controls

Chronic cough, dyspnea, chest tightness, chronic bronchitis (not ♂, N=41)

Cormier (1991) – Quebec (N=102)

Obstruction (FEV1/FVC, MMFR)

Choudat (1994) – France (N=102)

Lower but insignificant difference (MEF, FEF50, FEF25)

Cough (morning, diurnal, workplace), Work-related sneezing

Pedersen (1996) – Denmark (N=27)

Normal FEV1 More bronchial reactivity: (via bronchoscopy and BAL --increased lymphocytes, neutrophils, increased macrophage activity)

Larsson (1994) – Sweden (N=14, non-farmers)

BAL changes 1 day post exposure

Chronic Health Outcomes

AuthorsDeclines in Lung Function

Increased Respiratory Symptoms

Increased Airway Inflammation

Iverson (1990) – Denmark (N=124 pig, 57 dairy)

No difference in dairy vs pig farmer: FEV1 decrease 12 mL/year of farming

More wheezing, shortness of breath, dry cough compared to dairy farmer

Age, years in pig farming, and smoking all associated with bronchial hyperreactivity (PC20 histamine values)

Iversen (2000) – Denmark (7-yr follow up, N=135)

FEV1 declined more with pig farmer: 53 mL/yr pig (significant) vs 36 mL/yr dairy (not significant)No difference in FVC

Same as previous Small decrease in bronchial hyperreactivity between pig and dairy, only once correcting with FEV1

Vogelzang (2000) – Netherlands (N=171)

Mean FEV1: 73 mL/yr, FVC 55 mL/yr

n/a Increased bronchial responsiveness (associated with NH3, automated dry feeding, wood shavings as bedding)

Studies Relating Exposures to Outcomes

Contaminant Mean Conc.Recommendation To Prevent:

“Total” dust (A) 4.3 mg/m3

(P) 6.8 mg/m3(A) 2.4 mg/m3

(P) 3.8 mg/m3 Chronic cough & phlegm

Respirable dust (A) 0.33 mg/m3

(P) 0.34 mg/m3(A) 0.23 mg/m3

(P) 0.28 mg/m3 Chronic cough & phlegm;

frequent chest colds; febrile episodes

Endotoxin - total (A) 0.18 ug/m3

(P) 0.24 ug/m3(A) 0.08 mg/m3

(P) 0.09 mg/m3 FEV1

Endotoxin - respirable

(A) 0.17 ug/m3

(P) 0.23 ug/m3 n/a n/a

Ammonia 9 ppm 7 ppm FEV50, FEF50

Carbon dioxide 1740 ppm 1540 ppm FEV50, FEF50

Hydrogen sulfide n/d - -Carbon monoxide n/d -

Donham et al., 1989 (Sweden, N=57)

(A) Indicates area sample, (P) indicates personal sample


Contaminant Mean Conc. Recommendation To prevent:“Total” dust 4.53 mg/m3 1.3* – 2.8 mg/m3 <10% decrease in

FEV1 (>2 hr /day, 6 yr)

Respirable dust 0.23 mg/m3 - -Endotoxin – “total” 202.35 EU/m3 - -Endotoxin - respirable 16.59 EU/m3 - -Ammonia 5.64 ppm 7.5 ppm 3% decline in FEV1

Carbon dioxideHydrogen sulfideCarbon monoxide

Donham et al., 1995 (Iowa, N=201)

Not reported

*smokers had more response and effects not seen below 1.3 mg/m3


Contaminant Mean Conc.Recommended Exposure Limit Association?

“Inhalable” dust 2.63 mg/m3 2.6 mg/m3 YesEntotoxin 105 ng/m3 - NoAmmonia 1.6 mg/m3

(2.13 ppm)5.4 mg/m3 (7.2 ppm) Limited

Vogelzang et al. 2000: Examined bronchial hyperresponsiveness

Health & Medicine

Dr. Renée Anthony - Hazards and Prevention of Airborne Exposures and Risks