FLUORIDE STANDARDS AND PREDICTING WILDLIFE EFFECTS

J.R. Newman
Gainesville, Florida

Environmental Science and Engineering, Inc., P.O. Box ESE Gainesville, Presented at the 12th International Society for Fluoride Conference, St. Petersburg Beach, Florida, May 16-18, 1982.

SUMMARY: Federal and state clean air laws for the permitting of fluoride emission sources require evaluation of potential adverse ecological effects including those to wildlife and wildlife habitat. Although air quality permits and environmental assessments for fluoride emitting sources often cite compliance with various fluoride standards as demonstration of no adverse effects to wildlife, such use of these standards is inappropriate. A review of the literature regarding fluoride standards and ecological effects of fluoride reveals that adverse effects can occur to wildlife at or even below accepted fluoride standards. Alternative wildlife assessment methods including monitoring, predictive modeling, and sensitive receptor analyses are discussed.

Introduction

Fluoride emitting sources are subject to regulatory review and permitting under the Federal Clean Air Act and its 1977 amendments as well as under state clean air laws. Permitting involves documentation of compliance with accepted air quality standards as well as evaluation of potential adverse ecological effects, including effects on wildlife and wildlife habitat (1).

Although no national air quality standards exist for fluoride, environmental assessments for fluoride-emitting sources in the United States routinely cite compliance with state or other recommended fluoride standards to demonstrate no effect or no adverse effects to the environment. The objective of this paper is to assess the appropriateness of using fluoride standards to evaluate air quality impacts of fluoride emissions on wildlife

Permitting Process

According to the Clean Air Act, as amended on August 7, 1980, any new or modified air pollution source, exceeding specified regulatory emission potential, is subject to a pre-construction Prevention of Significant Deterioration (PSD) review process (2). Currently, fluoride is one of several pollutants regulated under the Clean Air Act. The Act designates that certain fluoride-emitting sources such as primary aluminum ore reduction plants, hydrofluoric acid plants, and phosphate rock processing plants are major sources and therefore subject to pre-construction review (1). States are required to develop their own air quality implementation plans. If the U.S. Environmental Protection Agency (EPA) approves the proposed plan, a state can then implement its own PSD permitting process.

The goals of the PSD review are to protect the public from any adverse effect that might occur at emission levels higher than the national ambient air quality standards; and to preserve, protect, and enhance air quality in areas of special natural, recreational, scenic, or historic value, such as national parks and wilderness areas. Major steps involved in the preconstruction review process are: demonstration of compliance with Ambient Air Quality Standards (AAQS); analysis of impacts on soils, vegetation, and visibility; and analysis of impacts on Class I areas (1).

Significant deterioration requiring detailed ecological assessment occurs when the amount of new air pollution exceeds the applicable maximum allowable increase ("increment") over a baseline concentration for a designated area. The amount of air pollution permissible or increment allowable varies with the classification of the area affected. Class I areas such as national parks and wilderness areas have the smallest PSD increments.

Fluoride Standards

Air quality standards are legal limits on levels of air emissions allowable in the ambient air or in other media for a given period of time. At least thirteen countries have national fluoride standards (3). Although the U.S. has no national fluoride standards, particulate fluoride is regulated under the National Ambient Air Quality Standards (NAAQS) for total suspended particulates (TSP). PSD increments for TSP have been established. Secondary standards for TSP are designed to protect public welfare including wildlife and wildlife habitat.

Twelve states have specific fluoride standards (4) including ambient air quality and forage tolerance standards (Table 1). Most of these states (i.e., Idaho, Kentucky, Maryland, New York, Montana, Texas and Washington) have forage standards which on a dry weight basis, are 40 ppm F- as a maximum annual average and 80 ppm F- as a maximum monthly average in or on vegetation. Wyoming has the lowest forage standard (25 ppm F-). Maryland has the most comprehensive fluoride standards of any state. Eleven different vegetative standards for maximum allowable fluoride levels have been adopted (5). State ambient air quality standards for gaseous fluoride are generally less than 1.0 ppb F- as a maximum monthly average and 4.5 ppb F- as a maximum 12 hour average (4).

Relationship of Fluoride Standards and Wildlife Protection

Often compliance with fluoride standards is used to claim no effect on wildlife. This was not the intended purpose when these standards were set. Although the effects of fluoride on wildlife are known, studies on their tolerance to given fluoride levels are few (6). Forage standards were developed to minimize the occurrence of economic damage of fluorosis in livestock (7), but in fact, there is evidence they do not (8-10). Fluorosis in wildlife has been reported even when compliance with state forage standards has been met (11).

Numerous reviews (6, 12-15) have described a variety of effects of fluoride in domestic animals and wildlife including acute exposure leading to gastroenteritis, muscular weakness, pulmonary congestion, respiratory and cardiac failure; and chronic exposure leading to dental lesions, lesions including fracturing, lameness, appetite impairment, poor reproduction, bioaccumulation, and behavioral changes. The primary route of fluoride exposure to animals is assumed to be by ingestion of fluoride-contaminated food or water (7). Fluoride is known to be more toxic to younger segments of animal population exhibiting bone growth and tooth development than in mature or older animals (12). Animals which are stressed or on low nutritional planes are more susceptible to fluoride toxicity than healthy animals (11,12). This observation is important when evaluating wildlife populations which are often exposed to greater natural or man-induced stresses, or on lower nutritional planes than their domesticated counterparts. These fluoride effects in wildlife can be grouped into five categories: mortality, morbidity, behavioral and physiological changes, body burdens of pollutants, and habitat changes (Fig. 1).

A comparison of the various state air quality standards for fluoride (5), (i.e., Kentucky, New Hampshire, New York, Texas, and Washington) with vegetation which was exposed to fluoride emissions (16-19) at or below these state air standards shows that vegetation injury can occur, and that the fluoride concentration in vegetation can exceed the recommended state vegetation standards. From a wildlife assessment perspective this means that habitat changes are possible even when ambient air quality compliance is achieved. In addition, studies on the setting and use of air quality standards including fluoride standards have shown that there is a great deal of variability in the response of organisms to air emission, in ambient air concentrations of fluoride for a given time period, and for concentrations of fluoride in or on vegetation (20-23). Because of these facts, air quality standards including forage standards for fluoride cannot be used as indicators of absolute protection. They may in fact not be indicators of even acceptable levels of wildlife protection.

Fluoride Impact Assessments

A more appropriate assessment of the impacts of fluoride emission on wildlife in the PSD process involves evaluation of the significance of the potential adverse effects. The significance of these effects depends upon the value society places upon the particular wildlife group affected by air emissions. For general wildlife species such as unprotected species, the threshold of significant effects may be considered to occur only at the highest level of effect, i.e., mortality. For highly valued species such as endangered species, the level of significance may be viewed by society to include all potential effects to the species (Fig. 1).

Proper wildlife impact evaluations require site-specific baseline evaluations of air quality (i.e. air monitoring and modeling) and more species-specific evaluations (i.e., sensitive receptor and pollutant fate analyses). If the value society places on potentially affected wildlife is high, i.e., endangered species, the number of significant adverse effects considerations increase (Fig. 1) as well as the scope of the required impact assessment. Where natural or man-made sources of fluoride already exist or are suspected to occur, monitoring of fluoride in air, water, soil, vegetation and wildlife will be needed to establish pre-existing conditions. Evaluation of other pre-existing stresses to wildlife and their habitat including natural stresses such as diseases, or man-induced stresses such as pesticide use is also desirable. This analysis is necessary to differentiate any conditions which may be attributed to fluoride such as vegetation damage due to insects.

For fluoride-emitting sources, both gaseous and particulate fluoride need to be modeled. Predicted fluoride concentrations for 1 hour, 3 hour, 24 hour, weekly, monthly, and annual average and maximum levels should be developed. Short term values should be reported on a seasonal basis. The selection of the reporting period should be a function of the growing season for vegetation in the area. Description of nocturnal and diurnal variations in ambient air concentrations of fluoride as well as the frequency of occurrence of the maximum levels may be necessary because of activity patterns of certain wildlife groups. Isopleths drawn on a wildlife resource map showing predicted concentrations of fluoride are recommended.

Fairly good information exists on effects of fluoride on vegetation to evaluate the potential changes to important wildlife habitat used for cover, shelter and food. The seasonal use of this habitat by key wildlife groups as well as the component of the habitat which is used, i.e. foliage for cover, fruits for food, etc., need to be identified. Lacking species-specific exposure response information, the use of analogous species responses or general vegetation responses may be required.

The wildlife sensitive receptor analysis used to determine potentially sensitive species is often most difficult because of incomplete wildlife effects information. The exposure potential for a given wildlife group may vary with the time of day or season, or with the habits of the species, i.e. resident or transient. With a transient species there may be a low likelihood of significant exposure. If the risk of exposure or exposure potential is low, then the significance of potential adverse effects may also be considered low. If the risk of exposure is high, monitoring of that particular wildlife population may be warranted for granting PSD permit approval.

In summary, the assessment of the effects of fluoride emissions on wildlife and their habitat, as required by Federal or state regulations, should be based on baseline monitoring, modeling, and sensitive receptor analyses, rather than demonstration of compliance with fluoride standards. The level and complexity of analysis is a function of the importance of the potentially affected wildlife species. Currently, regulatory review required by law, relies on existing fluoride research studies for predicting future effects. Most of these studies were not designed for such predictive purposes. Additional fluoride research that can be used in regulatory review for predicting the transport, fate and effects in wildlife and other biological groups is needed.

Acknowledgement

I would like to thank Dr. E.R. Hendrickson and J.H. Wiese for their critical reviews, T. Warrington and ESE Graphics Department for assistance in preparation of this manuscript.

References

1. Environmental Protection Agency. Prevention of Significant Deterioration Workshop Manual. U.S. Environmental Protection Agency, Office of Air, Noise, and Radiation, Office of Air Quality Planning and Standards. Research Triangle Park, N.C. 1980.

2. Code of Federal Regulations, Title 40, Part 52.21 for Prevention of Significant Deterioration (PSD) of Air Quality.

3. Newill, V.A.: Air Quality Standards. In: A.C. Stern, Ed. Air Quality Management, 3rd edition. Academic Press, New York, Vol. 5, 1977, pp. 445-504.

4. Bureau of National Affairs, Inc. Environmental Reporter: State Air Laws. Wash., D.C. Section 299 through 556, 1983.

5.Code of Maryland Regulations, Title 10, Health and Mental Hygiene, Subtitle 18, Air Quality; Adopted May 19, 1980;-Amended Oct. 3, 1980; Nov. 7, 1980; June 8, 1981; July 10, 1981; Aug. 11, 1981; Nov. 19, 1981.

6. Newman, J.R.: Animal Indicators of Air Pollution: A Review and Recommendation. Rep. CERL-006, U.S. EPA, Corvallis Environ. Res. Lab., Corvallis, Oregon, 1975, p. 192.

7. Shupe, J.L.: Clinical and Pathological Effects of Fluoride Toxicity in Animals. In: Carbon-Fluorine Compounds: Chemistry, Biochemistry and Biological Activities. CIBA Foundation Symposium (Sept. 13-15, 1971). ASP, Amsterdam, 1971, pp. 357-388.

8. Krook, L., and Maylin, G.A.: Industrial Fluoride Pollution. Chronic Fluoride Poisoning in Cornwall Island Cattle. Cornell Vet, 69 (suppl. 8): 1-70, 1979.

9. Crissman, J.W., Maylin, G.A., and Krook, L.: New York State and U. S, Federal Fluoride Pollution Standards Do Not Protect Cattle Health. Cornell Vet. 70:183-192, 1980.

10. Maylin, G.A., and Krook, L.: Milk Production of Cows Exposed to Industrial Fluoride Pollution. J. Toxicol. Environ. Health, 10:473-478,1982.

11. Newman, J.R., and Murphy, J.J.: Effects of Industrial Fluoride on Black Tailed Deer (Preliminary Report). Fluoride, 12:129-135, 1979. http://www.fluoridealert.org/f-deer.htm

12. National Academy of Science, Fluorides. Committee on Biological Effect of Atmospheric Pollutants. Nat. Res. Council, Wash., D.C., 1971, p. 29

13. Newman, J.R.: Effects of Industrial Air Pollution on Wildlife. Biol. Conserv. 15:181-190, 1979.

14. Newman, J.R.: Effects of Air Emissions on Wildlife Resources. U.S. Department of Interior, Fish and Wildlife Service, Biological Services Program, U.S. Government Printing Office, Washington, D.C. FWS/OBS/80/ 40.1, Air Pollution and Acid Rain Rept. No. 1, 1980, p. 32.

15. Lillie, R.J.: Air Pollutants Affecting the Performance of Domestic Animals. U.S. Dept. of Agriculture, Wash., D.C., USDA Handbook 380, 1970, P. 109.

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17. Adams, D.F., Hendric, J.W., and Applegate, H.G.: Relationship Among Periods, Foliar Burn, Fluorine Content of Plants Exposed to Hydrogen Fluoride. Agr. Food. Chem. 5:108-116, 1957.

18. Hitchcock, A.E., McCune, D.C., Weinstein, L.H., et al.: Effects of Hydrogen Fluoride Fumigation on Alfalfa and Orchard Grass: A Summary of Experiments from 1952 through 1965. Contrib. Boyce Thompson Inst. 24: 363-386, 1971.

19. Benedict, H.M., Ross, J.M., and Wade, R.W.: Some Response of Vegetation to Atmospheric Fluoride. J. Air Pollut. Control Assoc. 15:253-255,1965.

20. MacLean, D.C.: Air Quality Standards for Fluoride to Protect Vegetation: Regional, Seasonal and Other Considerations. J. Air Pollut. Control Assoc. 32:82-84, 1982.

21. Hendrickson, E.R.: The Fluoride Problem. In: Proceedings Impact of Air Pollution on Vegetation 6onference. Air Pollution Control Assoc. and Ontario Dept. of Energy and Resource Management. April 7-9, Toronto, 1970, pp. 1-13.

22. McCune, D.C.: Problems Involved in Devising Air Quality Criteria for the Effects of Fluorides on Vegetation. Amer. Indust. Hyg. Assoc. J., 32:697-701, 1971.

23. Munn, R.E., Phillips, and Sanderson, H.P.: Environmental Effects of Air Pollution: Implications for Air Quality Criteria, Air Quality Standards and Emission Standards. The Sci. Total Environ. 8:53-67, 1977.

To learn more about fluoride pollution, see www.fluoridealert.org/f-pollution.htm