Animal health risks

Animal Health Risk Management FIGURE 3. Chemical development interactions. 

Pestka, J.J. (2007). Deoxynivalenol toxicity, mechanisms and animal health risks. Anim. Feed Sci. Technol. 137 283-98. 

Health Safety. PET fibers pose no health risk to humans or animals. Eibers have been used extensively iu textiles with no adverse physiological effects from prolonged skin contact. PET has been approved by the U.S. Eood and Dmg Administration for food packagiug and botties. PET is considered biologically iuert and has been widely used iu medical iaserts such as vascular implants and artificial blood vessels, artificial bone, and eye sutures (19). Other polyester homopolymers including polylactide and polyglycoHde are used iu resorbable sutures (19,47). 

The detection and analysis, including quantification, of cyanobacterial toxins are essential for monitoring their occurrence in natural and controlled waters used for agricultural purposes, potable supplies, recreation and aquaculture. Risk assessment of the cyanobacterial toxins for the protection of human and animal health, and fundamental research, are also dependent on efficient methods of detection and analysis. In this article we discuss the methods developed and used to detect and analyse cyanobacterial toxins in bloom and scum material, water and animal/clinical specimens, and the progress being made in the risk assessment of the toxins. 

No more than 5.0% samples total coliform-positive in a month, (For water systems that collect fewer than 40 routine samples per month, no more than one sample can be total coliform-positive). Every sample that has total coliforms must be analyzed for fecal coliforms. There may not be any fecal coliforms or E. coli. Fecal coliform and E. coli are bacteria whose presence indicates that the water may be contaminated with human or animal wastes. Disease-causing microbes (pathogens) in these wastes can cause diarrhea, cramps, nausea, headaches, or other symptoms. These pathogens may pose a special health risk for infants, young children, and people with severely compromised immune systems. 

Recently, attention has focused on the potential hazardous effects of certain chemicals on the endocrine system because of the abihty of these chemicals to mimic or block endogenous hormones, or otherwise interfere with the normal function of the endocrine system. Chemicals with this type of activity are most commonly referred to as endocrine disruptors. Some scientists believe that chemicals with the ability to disrupt the endocrine system are a potential threat to the health of humans, aquatic animals, and wildlife. Others believe that endocrine disrupting chemicals do not pose a significant health risk, particularly in light of the fact that hormone mimics exist in the natural environment. Examples of natural hormone mimics are the isoflavinoid phytoestrogens (Adlercreutz 1995 Livingston 1978 Mayr et al. 1992). 

Sources of land pollution include direct dumping of domestic and industrial solid waste, excessive application of agrochemicals, and indirect contamination resulting from leaks or from leaching of hazardous components from liquid waste disposal sites or from atmospheric fallout. Land may also become contaminated by chemicals processed, stored or dumped at the site, perhaps in the distant past. Such contamination may pose a health risk to workers on the site, those subsequently involved in building, construction or engineering works, or the public (e.g. arising from trespass), and to animals. 

An inadequate intake in the diet of those food chemicals that are essential nutrients results in health risks. Indeed these risks are by far the most important in terms of the world s population where malnutrition is a major public health problem. But, unlike the toxic chemicals, they would show a very different dose-response if they were subject to similar animal bioassays. At very low doses there would be a high risk of disease that would decrease as the dose was increased, the curve would then plateau until exposure was at such a level that toxicity could occur. Figure 11.2 shows this relationship which is U- or J-shaped rather than the essentially linear dose-response that is assumed for chemicals that are only toxic. The plateau region reflects what is commonly regarded as the homeostatic region where the cell is able to maintain its function and any excess nutrient is excreted, or mechanisms are induced that are completely reversible. 

S.F. Sundlof and J. Cooper, Human health risks associated with drug residues in animal-derived foods, in Veterinary Drug Residues, Food Safety, ed. W.A. Moats and M.B. Medina, American Chemical Society, Washington, DC, pp. 5-17 (1996). 

The research strategies recommended by the USDA Research Planning Conference for EPA-related activities include studies ons (1) allelopathic effects on environment in terms of allelochemical persistence, activity and effectiveness, (2) ecological consequences due to alle-lochemicals, and (3) potential risks to human and animal health (37). In addition to these approaches, we should also pursue studies toward understanding the effect of ccrmercial allelochemicals, alone or in combination with other chemicals such as pesticides, on human health, safety and environment. 

No differences were noted in the litter sizes among those treated and the controls. No differences were noted in the number of stillborn pups or in pup weights. The study authors concluded that there was no evidence of adverse diisopropyl methylphosphonate-induced reproductive effects. However, as discussed in Section 2.2.2.1, there is some confusion regarding the actual doses to which the animals were exposed in the Hardisty et al. (1977) study. Therefore, results from this study are considered inappropriate for human health risk assessment. 

In broad terms risk assessments are carried out to examine the effects of an agent on humans (Health Risk Assessment) and ecosystems (Ecological Risk Assessment). Environmental Risk Assessment (ERA) is the examination of risks resulting from technology that threaten ecosystems, animals and people. It includes human health risk assessments, ecological or ecotoxicological risk assessments, and specific industrial applications of risk assessment that examine end-points in people, biota or ecosystems. 

Biocidal products are necessary for the control of organisms that are harmful to human or animal health and for the control of oiganisms that cause damage to natural or manufactured products. Although they are beneficial they can pose risks to humans, animals and the environment in a variety of ways due to their intrinsic properties and associated use patterns and therefore a comprehensive evaluation of the hazard and the risk and recommendations for safe use of such substances are required. In February... 

Studies in animals confirm that endrin s main target is the nervous system, probably because the brain and other parts of the nervous system contain much fatty tissue, and endrin tends to stay in those tissues. Birth defects, especially abnormal bone formation, have been seen in some animal studies. While there are no human data on birth defects, evidence in rodents suggests that exposure to high doses of endrin during pregnancy could be a health risk to developing fetuses. 

Human and animal evidence suggests there is a health risk for neurological effects only when exposures are high. There remains uncertainty in predicting dose levels for neurobehavioral effects, but 0.2 mg/kg body weight has been proposed as a threshold for convulsions in humans (Hayes 1963). 

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