# Presentation: 541442

## Health Concerns Associated with Airborne Exposure to AFO Contaminates

- Charles W. Purdy, DVM, PhD, USDA-ARS, Conservation & Prod. Research Lab., Bushland, Texas 79012; David C. Straus, PhD, Health Sciences Center, Texas Tech Univ., Lubbock, Texas 79430

## Objectives: 

- Are there aerosolized contaminants in Animal Feeding Operations that can make you sick?
- If so, what are the contaminants, where do they come from, and what amount causes sickness?

## Simple questions but no simple             			answers

- 	Why are there no simple answers:
**Aerosols** are **complex substances** in a constant state of flux.
**T**here is **no one right way to measure them.**
**T**here are **few aerosol standards**.
**Receptors** (living beings) are **highly individual in sensitivity.**

## What is the commonality for all    	Animal Feeding Operations?

- 1. Animals
- 2. Feed & Water
- 3. Animal Waste (urine and manure)
- 4. Odor
- 5. Dust
- 6. Environment to raise animals

## 	Inflammatory Conditions Associated with Certain Occupations                                           Including AFO

- A. Allergic Hypersentivities
- 		1. Pneumonitis
-        2. Upper respiratory tract (eg. rhinitis)
-        3. Skin
-        4. Neurological?
-  B. Organic Dust Toxic Syndrome  (Review Seifert, SA., et al., J Toxicol Clin Toxicol 2003;41:185-193)

## 	Inflammatory Condition (Syndrome) Associated Occupations

- C. Endotoxin Inflammatory rxn.
-     1. Fever: 4 to 12 hrs
-     2. Increase Leukocytes: 12 to 24hrs
-     3. Rapid repeated exposures develop   	short term tolerance
- D. Byssinosis (chronic respiratory disease of   textile workers)
- E. Infections?

## Most Probable Areas to Investigate 		AFO Toxic Aerosols

- 1. Manure (Dried or Wet) & Grain
- 	a. Bacteria (Toxins)
- 			1. Gram negative (endotoxin)
- 			2. Gram positive
- 	b. Fungi (Mycotoxins)
- 2. Particulates (Bioaerosols)
- 	a. PM10 or 10μm in diameter
- 	b. PM2.5 or 2.5μm in diameter

## Aerosol Research Results for CAFO Located in the Southern High Plains

- Andersen PM10 & PM2.5 (μg/m3)
- Andersen Bioaerosols (CFU/m3)
- Aerosolized Endotoxin Effects on Research Goats
- Treatment of Manure Dust & its Aerosolized Effects on Goats

## Justification

- Feedyard dust is the number 1 complaint by downwind neighbors
- Agriculture dust is regulated by EPA and state authorities (PM**10** avg. annual 50 μg/m3, 24 hr 150 μg/m3)
- Health implications for dust: **a**. ≤5 μm in diameter is considered respirable which can reach alveoli & induce lung disease. **b**. manure dust is high in endotoxins. **c**. manure dust contains viable microbes. **d**. manure dust can induce organic dust toxic syndrome.  **e**. manure dust can induce allergic hypersensitivity reactions

## Comparison of number of microorganisms & conc. of endotoxin in aerosols of 7 feedyards in summer & winter on the Southern High Plains (CFU/m3 ±SE; N=84)

| Bacteria | Winter | Summer  | P value | FY by season interaction |
| --- | --- | --- | --- | --- |
| Anaerobic | 508 (99) | 994 (243) | 0.02 | 0.001 |
| Mesophilic | 1225 (179) | 1658 (347) | 0.19 | 0.005 |
| Thermophilic | 29 (5) | 82 (18) | 0.001 | 0.002 |
| Enterococcus spp | 32 (9) | 50 (21) | 0.35 | 0.001 |
| Fungus |  |  |  |  |
| Mesophilic | 56 (8) | 101 (10) | 0.001 | 0.001 |
| Thermophilic | 2 (0.5) | 3 (0.8) | 0.24 | 0.005 |
| Total Microbes | 1852 | 2888 | NA | NA |
| Endotoxin | 8.37ng/m3  | 2.63ng/m3    | 0.05 | 0.05 |
| Purdy, et al, AJVR 2004;65:45-52 |  |  |  |  |

## Identification of Feedyard Bacteria and Fungal agents from Bioaerosols

- Eighteen Gram positive bacterial genera identified.
- Rare Gram negative bacterial genera identified (*Kingella kingae, Psychrobacter immoblis*).
- No culturable Gram negative enteric bacteria found (*E. coli, Salmonella,* etc)
- Twenty-two Fungal Genera: 5 most common ranked in desending order-  *Cladosporium spp, Alternaria spp, Aspergillus spp*, *Mucor spp*, and *Penicillium* *spp*
- Purdy, et al, AJVR 2004;65;45-52

## Overall General Linear Model (GLM) data for Andersen PM10, mean for 8 days, 4 FY, upwind & downwind, winter & summer

| Source | Pr>F | number | Mean(μg/m3) | StdE |
| --- | --- | --- | --- | --- |
| Model | <0.0001 | 128 | 179.7 | 19.6 |
| Location |  <0.001 |  |  |  |
| D wind | a* | 63 | 268.9 | 32.4 |
| U wind | b | 65 | 93.7 | 16.9 |
| Season | P <0.001 |  |  |  |
| Summer | a* | 64 | 261.8 | 34.3 |
| Winter | b | 64 | 97.7 | 12.9 |

## Overall GLM data for Andersen PM10, mean for 8 days, upwind & downwind, winter & summer                          (separate FY)

- Overall GLM data for Andersen PM**10**, mean for 8 days, upwind & downwind, winter & summer                          (separate FY)

| FYs | P >0.001 | number | Mean(μg/m3) | StdE |
| --- | --- | --- | --- | --- |
| FY1 | a* | 32 | 217.6 | 38.2 |
| FY2 | a | 32 | 225.8 | 52.1 |
| FY3 | a | 32 | 209.5 | 38.9 |
| FY5 | b | 32 | 66.1 | 8.5 |

## Overall GLM data for Andersen PM2.5, mean for 8 days, upwind & downwind, winter & summer                           (separate FY)

| FYs | P <0.005 | number | Mean(μg/m3) | StdE |
| --- | --- | --- | --- | --- |
| FY1 | a* | 32 | 24.0 | 2.2 |
| FY2 | a | 32 | 24.4 | 4.5 |
| FY3 | a | 32 | 26.5 | 4.7 |
| FY5 | b | 32 | 10.4 | 0.8 |
| * Mean with different letters are significantly different using Bonferroni’s t-test.
 |  |  |  |  |

## Overall GLM data for PM2.5, mean for 8 days, 4 FY, upwind & downwind, winter & summer

| Source | Pr>F | number | Mean (μg/
m3) | StdE |
| --- | --- | --- | --- | --- |
| Model | < 0.001 | 128 | 21.3 | 1.8 |
| Location | < 0.009  |  |  |  |
| D wind | a* | 64 | 25.1 | 2.5 |
| U wind | b | 64 | 17.6 | 2.5 |
| Season | <0.001 |  |  |  |
| Summer | a* | 64 | 27.7 | 3.2 |
| Winter | b | 64 | 15.0 | 1.2 |

## Overall GLM data for PM2.5, mean for 8 days, upwind & downwind, winter & summer (separate FY)

| FYs | P <0.005 | number | Mean(μg/m3) | StdE |
| --- | --- | --- | --- | --- |
| FY1 | a* | 32 | 24.0 | 2.2 |
| FY2 | a | 32 | 24.4 | 4.5 |
| FY3 | a | 32 | 26.5 | 4.7 |
| FY5 | b | 32 | 10.4 | 0.8 |
| * Mean with different letters are significantly different using Bonferroni’s t-test.
 |  |  |  |  |

## Effect of manure dust (containing natural endotoxins) on sheep & goats

- A. Dust affected by treatment
-      1. Autoclaved
-      2. Dry Heat
-      3. No treatment
- B. Dust contained 26.9μg endotoxin
- C. Coarse dust (range 0.89 to 356μm) mean 100μm; fine dust (range 0.88 t0 17.99) mean 7.7 μm
- Purdy, et al., SmRumRes 2002;46:123-132; 133-147.

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## Current Research Study: Determine effect of manure dust on alveolar macrophages

- No effect using coarse dust which was followed by tracheal instillation of *Mannheimia (Pasteurella) haemolytica* bacteria. Purdy, et al, Current Microbiol 2003;46:174-179.
- High mortality occurs using fine dust followed by tracheal instillation of *Trichoderma* *viride* fungal spores, however, no mortality occurred when the same fungal spore dose was given without dust. (Purdy, et al., 2005 Unpublished)

## Summary

- 1. No viable Gram negative enteric bacteria were found in feedyard aerosols.
- 2. Endotoxin is present in AFO coarse and fine dust aerosols.
- 3. Endotoxin is the most biologically active part of manure dust and it is stable at 212 C moist heat.
- 4. Endotoxin causes inflammatory reactions in both humans & animals.
- 5. Organic Dust Toxic Syndrome can be associated with AFO Aerosols & Aerosols from Handling Grain (Humans)

## Summary

- 6. Hypersensitive allergic reactions can follow fine dust (containing-pollens, mold spores, *Actinomytces*, mite parts) inhalation.
- 7. Fine dust (< 5μm in diameter) aerosols are more toxic in both animals and humans compared to coarse dust.
- 8. Bioaerosols are very complex substances.