County Regional Environmental
Evaluation KO-Alition
HEALTH ISSUES

A report on the effects of concentrated animal feeding operations (CAFOs).

Scientists say there is a link between swine and the spread of influenza (flu), which kills about 20,000 people in the U.S. annually. Pigs pick up the flu virus from wild aquatic birds, and pass it on to humans when they eat their breakfast sausages or ham sandwich.

Assessing the Risk and Extent of Endocrine Disruptors
The Canadian Centre for Occupational Health and Safety (CCOHS)

One of the most disquieting discoveries in recent years concerns the possible roles of environmental chemicals on endocrine systems. Endocrine systems are present not only in humans but in "higher" animals such as birds, fish, and mammals. Endocrine systems coordinate and regulate many important body functions such as growth and maturation, behaviour, reproduction and embryo development. They do this by making and releasing hormones which act as "chemical messengers." Certain tissues in the body have very specific receptors for the hormones. By interacting with these receptors, the hormones trigger responses.    [000802]

Endocrine Disruptors and Hog Manure
Environment Canada Science & Environment Bull., Nov/Dec. 1998 -

The concern, according to Environment Canada scientists, is that pig manure can contain high concentrations of endocrine-disrupting chemicals, including natural estrogens. These chemicals have been proven through various studies to have long-term adverse effects on the growth, development and reproduction of fish and wildlife. Runoff from fields treated with pig manure can enter adjacent streams or other bodies of water, resulting in eutrophication or even acute toxicity.     [991110}

Beware of On-Farm Manure Storage Hazards
Pub. S-82, Purdue University Cooperative Extension Service, West Lafayette, IN 47907 - Bill Field, Extension Safety Specialist

When animal waste of any type is being stored in large quantities, a number of hazards are present for both man and animal. The most obvious hazard is the potential danger of falling into one of the large open storage areas and drowning. There is also the danger from gases which are produced as the manure is decomposed by bacterial action. During the decomposition process, a variety of gases are released which can be hazardous to both people and livestock. The most common of these gases include: ammonia, carbon dioxide, methane, and hydrogen sulfide        [991025]

Effect and Magnitude of Agricultural Sources of Cryptosporidium in Surface Water
Ron Fleming, Doug Hocking, Heather Fraser and David Alves

In 1998, a study was begun at Ridgetown College, University of Guelph, to investigate levels of Cryptosporidium in livestock manure storages, tile drain water and surface water in southern Ontario. The objectives were:

1. to assess the viability of Cryptosporidium in liquid swine manure storages,
2. to determine the potential for a relationship between Cryptosporidium occurrence in storages and tile drains,
3. to quantify contributions from various sources in different watersheds, and
4. to investigate the relationship between the occurrence of Cryptosporidium and other water quality (and manure) indicators such as Giardia, E. coli and turbidity.

Ten swine farms were chosen and manure samples were collected over roughly a one-year period. Twenty tile drains were monitored (four samples from each during the period of flow in 1998/99). Half of these represented watersheds containing livestock. All of the swine farms and tile drain sites were also part of a study carried out in 1997, so much of the 1997 data could be used in the current study. In addition, eight surface water sites were chosen, and sampled between November, 1998 and May, 1999. These sites were chosen to represent a variety of typical land uses in an agricultural watershed.

Cryptosporidium was found in liquid swine manure, surface drain water, and subsurface tile drainage water. Both viable and non-viable oocysts were present in each of these. In total, 78 tile drain water samples were collected and analyzed. Each site was sampled four times. Each of the eight surface water sites was sampled four times. A total of six liquid manure samples were collected per farm from the 10 swine farms. The main findings of the study are as follows:

1. Conditions in a typical swine liquid manure storage are not such that there is a complete die-off of Cryptosporidium oocysts. Oocysts (non-viable and viable) were found in 22 of the 60 samples (37%). Viable oocysts were found in 19 of these 22 samples (86%). All manure storages tested positive at least once, of six sampling dates.

2. Concentrations of Cryptosporidium and Giardia in subsurface tile drains were significantly higher when the drainage area contained livestock barns than when no barns were present. Cryptosporidium concentrations averaged 771 and 323 oocysts per 100 L, respectively, when data from the 1997 and 1998/99 studies were combined.

3. Of 32 surface water samples, 14 (44%) tested positive for Cryptosporidium and the average concentration of all samples was 279 oocysts per 100 L (SD=564). No drainage area characteristics or combination of characteristics proved to be creating a significantly higher loading of oocysts than any other. This included presence of camping, field crops, houses, livestock, sewage treatment plant outfall, combined sewer outfall, migratory waterfowl or the date of sampling.

4. There was no significant relationship between E. coli concentrations or turbidity levels and concentrations of Cryptosporidium in the water samples.

5. There was no strong relationship between the presence or absence of Giardia and Cryptosporidium in the manure samples, though statistical modeling showed a trend for the presence of these variables to be associated.

6. The average viability of oocysts in surface water samples, expressed as a percentage of the total oocysts detected, was 71%. The corresponding value for tile drainage water was 72%. Of all the samples collected, 44% of surface water samples and 32% of tile water samples contained viable oocysts.

7. In the drainage areas with no barns and no (obvious) manure spreading, Cryptosporidium was detected at least once (of four sample dates) in the tile water at eight of ten sites.

There are several issues that this study raises where further investigation may be needed:

• In the tile drainage study, the evidence points to some contribution of Cryptosporidium that is related to livestock in those drainage areas having livestock barns. However, in the "non-barn" watersheds, what are the sources? This represents a significant background level.

• Tests are currently available to determine the source of Cryptosporidium organisms by examining the oocyst DNA. It may be necessary to use this approach on a watershed scale in order to accurately determine the source of contamination. Field-testing of this technique (or others) would be useful. It would allow for targeting of resources (e.g. where a cleanup is needed, or for identifying sources of recurring impairment).