National Dioxin Study - ACS Publications - American Chemical Society

Chapter 3 National Dioxin Study Paul E. des Rosiers

Downloaded by UNIV OF TEXAS AT AUSTIN on March 26, 2018 | https://pubs.acs.org Publication Date: April 24, 1987 | doi: 10.1021/bk-1987-0338.ch003

U.S. Environmental Protection Agency (RD-681), Washington, DC 20460

This report presents the results of EPA's investi gation of potential 2,3,7,8-TCDD (dioxin) contamination. The study represents a two-year, nationwide, multi-media evaluation initiated at the request of the U.S. Congress in 1983. The majority of dioxin contamination at Tier 1, 1a, 2 and 2a sites remained on-site. At sites where concentrated 2,4,5-TCP production wastes were stored or disposed, 2,3,7,8-TCDD concentrations were as high as 356 ppm. At most sites, however, 2,3,7,8-TCDD levels in soil were usually in the ppb range. In fish samples from nearby lakes and streams, 2,3,7,8-TCDD was measured in terms of ppt. Only two Tier 3 sites were extensively contaminated and comprised large facilities handling 2,4,5-T, 2,4,5-TP and 2,4,5-TCP with extent of contamin ation limited to one or two soil samples above 1 ppb. CDDs and CDFs were present in stack emissions from all sources tested in Tier 4 and most, but not a l l , of the combustion source categories reported in the literature. CDD and CDF emissions from some sources have estimated risks to the most exposed individual of 10 or more; these sources include a secondary copper smelting facil ity, a sewage sludge incinerator, and some municipal incinerators. At Tier 5 pastureland, rice field, and sugarcane sites, 2,3,7,8-TCDD levels in contaminated soils ranged from 0.6-564 ppt, with 67 percent below 5 ppt; levels in fish filets were between 8 and 23 ppt. At the three Tier 6 regionally selected sites, none was extensively contaminated. At one site, however, ground water contamination was found at the 0.07-0.10 ppt level in three samples. The Tier 7 investigation established the prevalence of 2,3,7,8-TCDD in the environment: 2,3,7,8-TCDD was detected infrequently and at very low levels in background soil samples with the highest level being 11.2 ppt. -5

This chapter not subject to US. copyright. Published 1987, American Chemical Society

Exner; Solving Hazardous Waste Problems ACS Symposium Series; American Chemical Society: Washington, DC, 1987.

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National Dioxin Study


Basis of Concern Numerous incidents of dioxin contamination have resulted i n a high l e v e l of public awareness and concern. This concern carries over into present e f f o r t s to implement cleanup actions and conduct disposal operations. Among the best known incidents was exposure of U.S. forces to Agent Orange i n Viet Nam. A defoliant, Agent Orange, was contaminated with 2,3,7,8-TCDD. A large number of suits was f i l e d against the manufacturers of these chemicals. These cases have now been settled out-of-court, thus the issue of cause and e f f e c t was not addressed. In Seveso, I t a l y , an i n d u s t r i a l accident involving 2,4,5trichlorophenol (2,4,5-TCP)/hexachlorophene (HCP) manufacture resulted i n widespread, low-level 2,3,7,8-TCDD contamination. Effects included evacuation of segments of the community, animal deaths, extensive cleanup e f f o r t s , and treatment of over 100 cases of chloracne alleged to be associated with the accident. In Times Beach, Missouri, waste o i l from 2,4,5-TCP/HCP manufacture, contaminated with 2,3,7,8-TCDD, was used to control dust on roads. The result was the well-known government 'buy-out* of the town. Use of waste o i l at several Missouri horse arenas resulted i n acute human health effects and the death of s i x t y - f i v e horses and several small animals. Subsequent use of the horse arena materials as f i l l at building construction s i t e s resulted i n further cleanup problems. 2,3,7,8-TCDD and other chemical contamination of adjacent land and water as a result of i n d u s t r i a l waste disposal at the Love Canal, 102nd Street, and Hyde Park s i t e s i n Niagara F a l l s , New York, posed health r i s k s . 2,3,7,8-TCDD contamination was also found to be extensive at the Vertac f a c i l i t y i n Jacksonville, Arkansas, both on- and o f f s i t e . In 1979, investigations at a municipal incinerator i n Hempstead, New York, led to the discovery that dioxins (CDDs) and furans (CDFs) were being emitted during the combustion process. In 1980, a PCB transformer f i r e i n the basement of the State Office Building i n Binghamton, New York, resulted i n d i s t r i b u t i o n of soot containing high levels of CDDs and CDFs, including the 2,3,7,8-isomers, throughout the building. Cleanup costs to date exceed the o r i g i n a l construction cost of the building. In 1981, reports from Canada demonstrated the presence of 2,3,7,8-TCDD i n Great Lakes f i s h . These reports coincided with reports of contamination of f i s h i n several U.S. r i v e r s , notably the Titabawassee River i n Michigan. 1

The National Dioxin Strategy At the time of the Congressional request for a study, the Environmental Protection Agency (EPA) was i n the midst of responding to contamination i n Missouri and other locations. EPA also had rulemaking proceedings underway to address various aspects of the dioxin problem.


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1

EPA s National Dioxin Study had three objectives: ° To study the extent of dioxin contamination and the associated r i s k s to humans and the environment; To implement or compel necessary cleanup action at contaminated s i t e s ; and ° To evaluate further both disposal alternatives to a l l e v i a t e current problems and regulatory alternatives to prevent future contamination. On December 15, 1983, EPA issued a "national dioxin strategy" for investigating, i d e n t i f y i n g , and cleaning up sites contaminated by dioxin (1). Within the framework of this strategy was a plan that called for research to be conducted on the technical f e a s i b i l i t y and economics of alternative methods for disposal and destruction of wastes and s o i l s contaminated by dioxin. To implement this strategy, EPA established seven categories ( t i e r s ) of investigation and study ranging from the most probable contamination to the l e a s t . These are: Tier 1. Tier 2.

Tier 3.

Tier 4.

Tier 5.

Tier 6.

Tier 7.

2,4,5-TCP production s i t e s and associated waste disposal s i t e s . Sites and associated waste disposal s i t e s where 2,4,5-TCP was used as feedstock for p e s t i c i d a l products. Sites and associated waste disposal s i t e s where 2,4,5-TCP and i t s derivatives were formulated into h e r b i c i d a l products. Combustion sources such as municipal and hazardous waste incinerators, PCB transformer/capacitor f i r e s , reactivation furnaces for spent granular activated carbon, boilers burning PCBs or pentachlorophenol (PCP)-treated wood, etc. Sites where herbicides derived from 2,4,5-TCP have been and are being used on a commercial basis such as rights-of-way, r i c e f i e l d s , forests, certain aquatic areas, and pastureland. Organic chemical and pesticide manufacturing f a c i l i t i e s where improper quality control of certain production processes would have resulted in the formation of 2,3,7,8-TCDD. Control s i t e s where contamination of 2,3,7,8-TCDD i s not suspected. These are to be compared with known contaminated s i t e s to form a background l e v e l for the strategy studies.

T o x i c i t y Equivalence While the primary focus of this study was on contamination associated with 2,3,7,8-TCDD, EPA was also concerned with human exposure from other isomers of chlorinated dibenzo-p-dioxin and dibenzofuran. EPA (2) and others have developed a number of weighting schemes to compare the t o x i c i t i e s of various chlorinated dioxin and furan isomers to that of 2,3,7,8-TCDD, the most studied, and generally considered to be the most toxic isomer. Toxicity



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Equivalence Factor (TEF) approaches express the t o x i c i t y of CDD/CDF mixtures i n terms of "2,3,7,8-TCDD equivalents." This allows comparison of the t o x i c i t y of mixtures for purposes of r i s k assessment and remedial action planning. EPA's TEFs for isomers and homologs of CDD/CDF are shown i n Table 1. With the exception of 2,3,7,8-TCDD, the 2,3,7,8-substituted HxCDDs and 2,3,7,8-TCDF, these TEFs are not based on the results of major animal (reproductive, carcinogenic) studies. Generally, TEFs are based on estimates of the r e l a t i v e t o x i c i t y from i n v i t r o tests whose relationship to the chronic effects of concern i s largely presumptive. Nevertheless, studies on systemic effects continue to reinforce the view that the short-term assays provide important fundamental information on the t o x i c i t y of the CDDs/CDFs. Tiers 1 and 2/la and 2a, Production and Disposal Sites Tier 1 comprises 2,4,5-TCP production s i t e s and associated waste disposal s i t e s (Tier l a ) ; whereas Tier 2 represents s i t e s where 2,4,5-TCP was employed as a precursor i n the manufacture of pesticides such as 2,4,5-T, 2,4,5-TP (Silvex), or hexachlorophene, and associated waste disposal s i t e s (Tier 2a). EPA used a three-phased approach. F i r s t , information was collected to i d e n t i f y these s i t e s . EPA then used i t s enforcement authorities to v e r i f y production f a c i l i t i e s and associated waste disposal s i t e s . As needed, EPA collected additional data from s i t e v i s i t s and employee interviews. Next, EPA screened the sites through f i e l d testing to determine actual 2,3,7,8-TCDD contamination. EPA employed a biased sampling approach. Instead of taking samples randomly, EPA sampled i n the locations most l i k e l y to be contaminated with dioxin ( i . e . , loading, storage, or production areas). If o f f s i t e migration of contaminated material was suspected, EPA sampled outside the f a c i l i t y boundary. Quality assurance/quality control protocols, following Superfund-authorized procedures, were developed to ensure that a l l data generated would be of known quality. F i n a l l y , i f a l e v e l of 2,3,7,8-TCDD contamination requiring a cleanup response ( i . e . , >1 ppb) was i d e n t i f i e d , p o t e n t i a l l y responsible parties (PRPs) were encouraged to take appropriate response action. If necessary, response a c t i v i t i e s were performed under Superfund. A l l a c t i v i t i e s were coordinated with state and l o c a l authorities as well as other federal agencies such as the Centers for Disease Control (CDC), the National Institute for Occupational Safety and Health (NIOSH), the Food and Drug Administration (FDA), and the Federal Emergency Management Agency (FEMA). Community relations played an important role i n a l l a c t i v i t i e s conducted during the i d e n t i f i c a t i o n , screening, and cleanup of dioxin-contaminated s i t e s .


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Table 1.

2,3,7,8-TCDD Other TCDDs Penta-CDDs Hexa-CDDs Hepta-CDDs Octa-CDD 2,3,7,8-TCDD Other TCDFs Penta CDFs Hexa-CDF Hepta-CDFs Octa-CDF


b

b

b

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Relative Potency Factors Used i n Estimating 2,3,7,8-TCDD Equivalents

Compound(s)

a

H A Z A R D O U S

Relative Potency Factor or TEF

a

1.0 0.01 0.5 0.04 0.001 0.000 0.1 0.001 0.1 0.01 0.001 0.000

Relative potency factor for the most toxic 2,3,7,8substituted isomer. TEF = toxic equivalence factor = r e l a t i v e t o x i c i t y assigned. CDD or CDF concentration x TEF = 2,3,7,8-TCDD equivalents. In situations where 2,3,7,8-TCDD or -TCDF was not chemically analyzed i n the sample, then TCDDs and TCDFs w i l l have a r e l a t i v e potency factor of 1.0 and 0.1, respectively.

Results. O r i g i n a l l y , about 450 Tier 1 and 2 sites (50 production s i t e s and about 400 associated waste disposal s i t e s ) were expected. After systematic searching, the number of s i t e s has been more c l e a r l y defined. In t o t a l , there were 99 dioxin sites i n Tiers 1 and 2. Table 2 shows a breakdown of s i t e s by t i e r 03): Table 2. Tier 1 la 2 2a

Dioxin Sites by Tier Number of Sites 11 53 9 26

Tier 1 and 2 s i t e s are located i n six of the ten EPA Regions. Figure 1 i s a graphic representation of dioxin-contaminated s i t e locations by Region (3). Seventeen dioxin s i t e s are on the current Superfund National P r i o r i t i e s L i s t (NPL); four more have been proposed i n Updates 2 and 3 to the NPL. Most of these NPL s i t e s , such as Love Canal



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TOTALS TIER 112: 20 TIER 1A t 2A: 79 REFERRALS: 10

Figure 1.

Regional D i s t r i b u t i o n of Dioxin T i e r 1/Tier 2 Sites


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i n Niagara F a l l s , New York, are on the NPL for chemical contamination problems i n addition to dioxin. The 21 s i t e s on the NPL or proposed NPL (Updates 2 or 3) are (3): Cashel Residence Conservation Chemical Diamond Shamrock Drake Chemical Fike Chemicals Hooker Chemical (Hyde Park) Hooker Chemical (Love Canal) Hooker Chemical (S-Area) Hooker Chemical (102nd St.) Minker Residence Moyers L a n d f i l l NIES Quail Run Rohm & Haas Romaine Creek Shenandoah Stables Stout Residence S u l l i n s Residence Times Beach Vertac Western Processing

Fenton, MO Kansas City, MO (Update 3) Newark, NJ Lock Haven, PA Nitro, WV Niagara F a l l s , NY Niagara F a l l s , NY Niagara F a l l s , NY Niagara F a l l s , NY Imperial, MO C o l l e g e v i l l e , PA Furley, KS (Update 2) Gray Summit, MO (Update 2) B r i s t o l , PA (Update 3) Imperial, MO Moscow M i l l s , MO Imperial, MO Fenton, MO Times Beach, MO Jacksonville, AR Kent, WA

Under the National Dioxin Strategy, s i t e s found to be contaminated i n Tiers 3 through 7 are referred to the Office of Solid Waste and Emergency Response (OSWER) f o r possible Superfund (CERCLA) action. These s i t e s are then considered along with the s i t e s i n Tiers 1 and 2 and a l l other hazardous waste s i t e s managed under the Superfund program. A d d i t i o n a l l y , the EPA Regions are responding to several s i t e s , not i d e n t i f i e d through the National Dioxin Strategy, where dioxin may be present. Following i s a l i s t of the ten dioxin r e f e r r a l sites: Bogle Dioxin Site Chem A l l , Inc. (Sonford Chemical) Chemspray Inc. (Agrisystems) E.T.M. Enterprises (Parsons Chemical Works, Inc.) Farmingdale Garden Labs Riverdale Chemical Co. Smith-Douglas Stauffer Chemical (Montrose Chemical) Union Carbide A g r i c u l t u r a l Products W.A. Cleary

Alexandria, VA Port Neches, TX Belleglade, FL Grand Ledge, MI Farmingdale, NY Chicago Heights, IL Norfolk, VA Henderson, NV St. Joseph, MO Somerset, NJ

Of the 99 Tier 1 and 2 production and waste disposal s i t e s , ten are c l a s s i f i e d as requiring "no further action" under the Strategy based on sampling results indicating very low or undetectable levels of 2,3,7,8-TCDD. These s i t e s are:


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Calgon Corporation Drake Chemical Eastman Kodak Georges Creek GROWS Millmaster Onyx Moyers L a n d f i l l Rhone-Poulenc South Charleston L a n d f i l l Union Carbide

Pasadena, TX Lock Haven, PA Rochester, NY Poca, WV M o r r i s v i l l e , PA Berkeley Heights, NJ C o l l e g e v i l l e , PA Portland, OR South Charleston, WV South Charleston, WV

Of those s i t e s where dioxin was detected at levels of concern, the most common materials contaminated were s o i l and dust. At certain s i t e s , production waste, contaminated equipment, and contaminated building materials were found. As expected, these s i t e s were generally the production f a c i l i t i e s of Tiers 1 and 2 and those waste disposal s i t e s where intact waste or scrapped equipment was stored or disposed. The majority of dioxin contamination at Tier 1, l a , 2 and 2a s i t e s remained on-site. Furthermore, the 2,3,7,8-TCDD was usually confined to areas where waste materials were stored, loaded, processed, or, i n the case of 28 Missouri s i t e s , sprayed on roads to control dust. In seven cases, o f f s i t e migration at levels of concern has been confirmed. They are: Diamond Shamrock Brady Metals Love Canal 102nd Street Hyde Park Vertac B l i s s Tank Property

Newark, NJ Newark, NJ Niagara F a l l s , NY Niagara F a l l s , NY Niagara F a l l s , NY Jacksonville, AR Frontenac, MO

Levels of Contamination. Where 2,3,7,8-TCDD was detected, levels generally were highest i n the v i c i n i t y of actual waste handling operations (e.g., processing, loading, and storage). At s i t e s where concentrated 2,4,5-TCP production wastes were stored or disposed, 2,3,7,8-TCDD concentrations were as high as 356 ppm. At most s i t e s , however, 2,3,7,8-TCDD levels i n s o i l were usually i n the ppb range. In f i s h samples from nearby lakes and streams, 2,3,7,8-TCDD was measured i n terms of ppt. Cleanup A c t i v i t i e s . Cleanup actions have focused on reducing potential exposure through inhalation or ingestion of dioxincontaminated s o i l s or dust. Many techniques have been developed and/or evaluated by the EPA Office of Research and Development (4) and have been employed by OSWER and others i n cleanup activities. Tier 3, Formulators Tier 3 consists of f a c i l i t i e s and associated waste disposal s i t e s where 2,4,5-TCP and i t s derivatives were formulated into


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p e s t i c i d a l products. Generally, these products are herbicides, i n s e c t i c i d e s , fungicides, and germicides: 2,4,5-trichlorophenol (2,4,5-TCP) 2,4,5-trichlorophenoxyacetic acid (2,4,5-T) silvex (2,4,5-TP)


erbon ronnel hexachlorophene

isobac 20

fungicide, bactericide plant hormone; herbicide; defoliant herbicide; plant growth regulator herbicide insecticide topical anti-infective (restricted); germicidal soaps; veterinary medicine topical anti-infective (restricted); germicidal soaps; veterinary medicine

Figure 2 depicts sampling locations n a t i o n a l l y . Findings. EPA estimates that approximately 8 percent of the 312 f a c i l i t i e s i d e n t i f i e d i n the FATES database are contaminated above 1 ppb i n s o i l or above detection l i m i t s of approximately 10 ppq - 1 ppt i n other media. At dioxin-contaminated s i t e s , the extent of contamination was usually limited to one or two s o i l samples with concentrations of 2,3,7,8-TCDD above 1 ppb. Only two Tier 3 s i t e s were extensively contaminated and comprised large handlers of 2,4,5-T, 2,4,5-TP, or 2,4,5-TCP (_5). Tier 4, Combustion Sources This section summarizes the findings of Tier 4, the portion of the study dealing with combustion sources. Tier 4 was designed as a screening study to determine which combustion source categories emit CDDs and at what concentrations. The main focus was on releases to the ambient a i r ; however, other samples, such as ash and scrubber water, were also obtained to determine i f these compounds were released to other media. Because some combustion sources were known to emit a wide range of CDDs and CDFs, Tier 4 samples were analyzed f o r s p e c i f i c groups (homologs) of CDD and CDF compounds, as well as for 2,3,7,8-TCDD, the compound of most concern. There are m i l l i o n s of combustion sources i n the United States. Residential heating units burn o i l , gas, coal and wood for heat. Larger commercial, i n s t i t u t i o n a l , and u t i l i t y boilers burn f o s s i l fuels to generate heat and e l e c t r i c i t y . Many i n d u s t r i a l processes involve the combustion of fuels and other raw or waste materials to produce heat and/or recover products of marketable value. Other processes, such as incineration, use combustion to reduce the volume of unwanted waste products and to recover heat and



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Statistical

Regional

41

23

5

6

Number of s i t e s sampled Number of s i t e s c o n t a m i n a t e d * (•)

Number of s i t e s n o t contaminated (o) 36 17 *More than 1 ppb i n s o i l o r d e t e c t a b l e l e v e l s i n o t h e r media. F i g u r e 2. L o c a t i o n s of Sampled T i e r 3 S i t e s .


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other resources from the waste products. Open f i r e s , both a c c i dental (e.g., s t r u c t u r a l and forest f i r e s ) and intentional ( i . e . , those set for forest management and a g r i c u l t u r a l burning), are other examples of combustion sources. Assessment of CDD and CDF emissions from combustion sources has received limited study. Previous work included studies of emissions from hazardous waste incinerators, u t i l i t y b o i l e r s , and municipal waste combustion. Even for those source categories that had previously been tested, there i s considerable variation i n the extent and quality of testing and the test methods employed. Study Design. The large number of combustion source categories made i t impractical to test each under Tier 4. A study plan was developed that i d e n t i f i e d those source categories that were believed to have the greatest potential for emitting CDDs to the atmosphere. Selection and p r i o r i t i z a t i o n of source categories for testing were based upon a review of CDD-related studies reported i n the l i t e r a t u r e and engineering judgment. Information from this review suggested that the following conditions were most important f o r CDD formation: o o o

Presence of CDD i n the materials being burned; Presence of CDD precursors i n the materials being burned (e.g., chlorinated phenols, chlorinated benzenes); and Presence of chlorine, f u e l , and combustion conditions conducive to CDD formation, including: ° Relatively low combustion temperature (500-800°C); ° Short residence time of fuel i n the combustion zone (

z o X > N

o

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Table 4. T i e r 4 and Other Sources L i s t e d i n Rank Order by 2,3,7,8-TCDD Concentrations (6) (ng/dscm @ 3% 0 )

a

2

1

12 ,3,7,8-TCDD T o t a l CDDs T o t a l CDFs


Source *Secondary Copper Smelterb M u n i c i p a l Waste I n c i n e r a t o r - P l a n t M u n i c i p a l Waste I n c i n e r a t o r - P l a n t i n d u s t r i a l Waste I n c i n e r a t o r Hazardous Waste I n c i n e r a t o r M u n i c i p a l Waste I n c i n e r a t o r - P l a n t M u n i c i p a l Waste I n c i n e r a t o r - P l a n t *Wood-fired B o i l e r *Sewage Sludge I n c i n e r a t o r - P l a n t C *Wire Reclamation I n c i n e r a t o r *Sewage Sludge I n c i n e r a t o r - P l a n t A *Drum and B a r r e l Furnace Hospital Incinerator Municipal Incinerator-Plant F Municipal Incinerator-Plant C | * I n d u s t r i a l Carbon Regenerator M u n i c i p a l Carbon Regenerator * K r a f t Paper Recovery B o i l e r - P l a n t l*Sewage Sludge I n c i n e r a t o r - P l a n t B |*Kraft Paper Recovery B o i l e r - P l a n t |*Kraft Paper Recovery B o i l e r - P l a n t I (Co-fired Boiler) I Coal-fired U t i l i t y Boilers I (7 p l a n t s ) a

b

| B |

E| j

| D| A |

| | j I

| j j

| | | c|

| BI

a |

I I

170 26 16 4.5 1.4 0.8 0.7 0.28 0.14 0.07 0.05 0.05 ND NR NR ND ND ND ND ND ND ND NR C

d

|

16,000 6,400 4,300 630 77 710 53 200 53 440 20 5 330 210 46 3.7 3.3 2.9 1.6 1-2 0.7

j I

ND ND

! ! I 1

I | I |

I I 1

I | | 1

65,000 11,600 5,300 2,400 190 150 I 260 1 83 I 450 I 580 | 44 1 27 I 735 I 250 I 120 I 3.3 | 4.8 1 2.1 | 28 | 0.7 | 0.6 | ND | ND

1

ng/dscm @ 3% On = nanograms per standard cubic meter o f f l u e gas normalized to 3 percent oxygen. D a t a reported f o r t h i s s i t e are "estimated minimum." The true value may be h i g h e r . ND - Not detected, g e n e r a l l y a t l e s s than 1 ng/dscm @ 3% 0 « NR » Not r e p o r t e d .

C

2

d

o

Considering the fact that T i e r 4 focused on source categories and i n d i v i d u a l sources that were generally believed to have an above-average potential to emit CDD compounds, the results suggest that routine emissions of CDD and CDF compounds from many combustion source categories may not present a s i g n i f i c a n t problem. However, since only a r e l a t i v e l y small number of sources were tested, some sources that were not tested might also have CDD and CDF emissions that could result i n elevated r i s k s .

Future Work. Although the majority of the planned Tier 4 study has been completed, there are a number of continuing e f f o r t s that EPA plans to pursue with respect to CDD emissions from combustion sources. These include the following: o

A detailed technical report describing the Tier 4 program w i l l be prepared once a l l of the data (e.g., ash data) has been analyzed and interpreted. Completion of the Tier 4 technical report i s scheduled f o r late 1986.

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o

o


o

o

H A Z A R D O U S

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P R O B L E M S

EPA i s currently considering whether CDDs should be l i s t e d as a hazardous a i r pollutant category. A decision on whether to l i s t CDD i s expected by spring of 1987. EPA has a project underway to respond to the requirements of Section 102 of the Hazardous and Solid Waste Act of 1984 (HSWA) concerning CDD emissions from municipal incinerators. This e f f o r t i s intended to i d e n t i f y design and operating guidelines to minimize CDD emissions. EPA w i l l continue to coordinate with other environmental protection agencies (e.g., Environment Canada and the State of New York) i n order to obtain the CDD/CDF test data that are currently being c o l l e c t e d . It i s expected that data for several municipal incinerator tests w i l l be released by New York State l a t e r i n 1986. EPA plans to continue i t s e f f o r t s to standardize and refine stack sampling and a n a l y t i c a l procedures that w i l l r e f l e c t improvements i n the state-of-the-art. The recommended ASTM stack test methodologies for municipal incinerators are currently under EPA review and evaluation.

Tier 5, Use Sites Tier 5 s i t e s comprise areas where 2,4,5-TCP and p e s t i c i d a l derivatives (including 2,4,5-T, Silvex, hexachlorophene, Erbon, Ronnel, and Isobac 20) were or are being used on a commercial basis. In this t i e r , a s t a t i s t i c a l sample was not possible due to the variety uses and conditions. Tier 5 sampling was generally limited to those areas where the use of 2,4,5-T or Silvex has been documented, since information from the EPA Office of Pesticide Programs indicated that these two compounds have been more heavily used i n s p e c i f i c areas and thus have a greater potential for causing s i g n i f i c a n t human exposure to dioxin. The other compounds were of lesser interest due to: (a) low levels of active ingredient pesticide i n the end-products; (b) use on very small areas; or (c) a wide d i v e r s i t y of uses at low levels of application. Lack of documentation on use also made i t impractical to focus on these other compounds. A t o t a l of 26 Tier 5 s i t e s was sampled, including s i x forest s i t e s , seven r i c e f i e l d s , two canals adjacent to sugarcane f i e l d s , one sugarcane f i e l d , three rights-of-way, three rangeland areas, one multiple use area, and three aquatic s i t e s (used for recreation, f i s h e r i e s , or multiple uses). The environmental media to be sampled were determined by the EPA regional o f f i c e s on a s i t e - b y - s i t e basis. They included s o i l s , stream sediments, f i s h tissue, vegetation, and animal tissue. A l l analyses were done at detection levels of approximately 1 ppt, because s o i l concentrations below 1 ppb can be of concern i n certain types of areas, such as grazing lands. Results. 2,3,7,8-TCDD has been detected at 15 of the 26 s i t e s including two rights-of-way, one aquatic use s i t e , two sugarcane f i e l d s , canals adjacent to one sugarcane f i e l d , four r i c e f i e l d s , three forest areas, one rangeland area, and one multiple use area.


3.

D E S

ROSIERS


49


Over 40 percent of the s o i l and sediment samples taken at contaminated sites had 2,3,7,8-TCDD present above the detection l i m i t of approximately 1 ppt (5). Two s i t e s had detectable levels i n f i s h . At one of these, a l l f i s h samples were contaminated at levels up to 23 ppt i n f i l e t s . 2,3,7,8-TCDD levels i n s o i l s at contaminated s i t e s were between 0.6 and 564 ppt with 67 percent below 5 ppt; levels i n sediments were between 0.7 and 200 ppt with 61 percent below 5 ppt; and levels i n f i s h f i l e t s were between 8 and 23 ppt. No 2,3,7,8-TCDD was detected i n animal tissue or vegetation samples collected from land used for grazing or r a i s i n g crops; however, only a limited number of these samples was c o l l e c t e d . Findings. Since the source of 2,3,7,8-TCDD at the one severely contaminated Tier 5 s i t e (Petenwell Flowage, Wisconsin) does not appear to be related to pesticide use, further national investigation of T i e r 5 s i t e s does not appear to be warranted. However, as described i n greater d e t a i l under the Tier 7 discussion, further investigations of pulp and paper m i l l s are being conducted. Tier 6, "Other" Chemical Manufacturers Tier 6 consists of organic chemical and pesticide manufacturing f a c i l i t i e s where improper quality control within production processes could cause products or waste streams to become contaminated with 2,3,7,8-TCDD. F a c i l i t i e s producing any of sixty selected compounds were i d e n t i f i e d . The objective of the sampling for this t i e r was to determine the percentage of f a c i l i t i e s with concentrations of 2,3,7,8-TCDD above 1 ppb i n s o i l or at detectable levels i n other environmental media (e.g., f i s h i n nearby streams). Findings. EPA estimates that 9 percent of the 66 f a c i l i t i e s o r i g i n a l l y i d e n t i f i e d as Tier 6 s i t e s are contaminated. None of the three s i t e s was extensively contaminated with 2,3,7,8-TCDD (5). Based on these findings, further national investigation of Tier 6 s i t e s for 2,3,7,8-TCDD does not appear to be warranted. Tier 7, Background

Sites

Tier 7 consists of s i t e s that did not have previously known sources of 2,3,7,8-TCDD contamination. The Tier 7 investigation was intended to establish the prevalence of 2,3,7,8-TCDD i n the environment and to provide a basis for comparison with results from the other t i e r s . The s p e c i f i c objectives of the sampling were to: o

o

Determine the percentage of s i t e s i n the EPA Urban and Rural S o i l Networks that have detectable levels of 2,3,7,8TCDD i n s o i l at a detection l i m i t of approximately 1 ppt. Determine the percentage of s i t e s i n the combined U.S. Geological Survey's (USGS) National Stream Quality Accounting Network and Benchwork Network that have detectable levels of 2,3,7,8-TCDD i n f i s h tissue at a detection l i m i t of approximately 1 ppt.


50

S O L V I N G

H A Z A R D O U S

W A S T E

P R O B L E M S

Findings. Of the s t a t i s t i c a l l y selected s o i l s i t e s , 142 of 200 rural and 221 of 300 urban s i t e s were sampled. The remaining 58 r u r a l s i t e s and 79 urban s i t e s could not be sampled because of d i f f i c u l t y i n locating the s i t e (130 s i t e s ) or because permission to c o l l e c t a sample was denied (7 s i t e s ) . Of the 100 s t a t i s t i c a l l y selected f i s h s i t e s , 90 were sampled. The remaining ten s i t e s could not be sampled because of lack of water, f i s h , or success i n catching f i s h at the time sampling was attempted. Soil


°

2,3,7,8-TCDD was detected infrequently and at very low levels i n background s o i l samples. 17 of 221 urban sites and 1 of 138 r u r a l s i t e s had detectable l e v e l s , with the highest l e v e l found being 11.2 ppt (5).

Fish °

2,3,7,8-TCDD was detected more frequently i n background f i s h samples. EPA estimates that 21 percent of the USGS national national monitoring network s i t e s have detectable l e v e l s . The frequency of detection i s greater (31 percent) at s i t e s selected by EPA's regional o f f i c e s , many of which are near i n d u s t r i a l and urban areas.

°

An even higher proportion (23 of 29) of Great Lakes' f i s h sampling s i t e s had detectable l e v e l s , which i s consistent with previous findings and i s not surprising since the type and size of f i s h sampled i n the Great Lakes and the long water retention times tend to increase the potential f o r bioaccumulat ion.

°

2,3,7,8-TCDD levels i n f i l e t samples could be a cause f o r concern at s p e c i f i c locations under certain consumption patterns; l o c a l exposure conditions need to be evaluated to determine a l e v e l of concern for those areas.

°

Fish and s h e l l f i s h from estuarine and coastal waters are rarely contaminated; two of the three s i t e s where 2,3,7,8TCDD was detected are i n areas heavily influenced by i n d u s t r i a l discharges.

°

Certain types of pulp and paper m i l l discharges need to be further evaluated as possible sources of 2,3,7,8-TCDD. Both EPA and the industry are undertaking more detailed investigations.

Summary of Pertinent Regulations As defined i n the RCRA d i o x i n - l i s t i n g rule (7), which became e f f e c t i v e on July 15, 1985, the waste streams designated as acutely hazardous are:


3.

D E S

ROSIERS


51


F020 - Wastes (except wastewater and spent carbon from HC1 p u r i f i c a t i o n ) from the production or manufacturing use (as a reactant, chemical intermediate, or component i n a formulating process) of t r i - or tetrachlorophenol, or of intermediates used to produce their pesticide derivatives. (This l i s t i n g does not include wastes from the production of hexachlorophene from highly p u r i f i e d 2,4,5-TCP.) F021 - Wastes (except wastewater and spent carbon from HC1 p u r i f i c a t i o n ) from the production or manufacturing use (as a reactant, chemical intermediate, or component i n a formulating process) of pentachlorophenol, or of intermediates used to produce i t s derivatives. F022 - Wastes (except wastewater and spent carbon from HC1 p u r i f i c a t i o n ) from the manufacturing use (as a reactant, chemical intermediate, or component i n a formulating process) of t e t r a - , penta-, or hexachlorobenzenes under alkaline conditions. F023 - Wastes (except wastewater and spent carbon from HC1 p u r i f i c a t i o n ) from the production of materials on equipment previously used for the production or manufacturing use (as a reactant, chemical intermediate, or component i n a formulating process) of t r i - and tetrachlorophenols. (This l i s t i n g does not include wastes from equipment used only for the production or use of hexachlorophene from highly p u r i f i e d 2,4,5-TCP.) F026 - Wastes (except wastewater and spent carbon from HC1 p u r i f i c a t i o n ) from the production of materials on equipment previously used for the manufacturing use (as a reactant, chemical intermediate, or component i n a formulating process) of t e t r a - , penta-, or hexachlorobenzene under alkaline conditions. F027 - Discarded unused formulations containing t r i - , t e t r a - , or pentachlorophenol or discarded unused formulations containing compounds derived from these chlorophenols. (This l i s t i n g does not include formulations containing hexachlorophene synthesized from prepurified 2,4,5-TCP as the sole component.) F028 - Residues r e s u l t i n g from incineration or thermal t r e a t ment of s o i l contaminated with EPA hazardous waste codes F020, F021, F022, F023, F026, and F027. Moreover, this rule replaced the regulation concerning the disposal of 2,3,7,8-TCDD-contaminated waste under the Toxic Substances Control Act (TSCA)—the so-called Vertac Rule—which was revoked on the same date. Unfortunately, the d i o x i n - l i s t i n g rule currently does not cover thermally stressed PCBs, a source of CDDs and CDFs



52

SOLVING HAZARDOUS WASTE PROBLEMS

from transformer and capacitor f i r e s (8) and i n abandoned hazardous waste s i t e s . The rule, however, may be modified to l i s t this category i n the future. Land disposal of the l i s t e d wastes must be conducted pursuant to additional s p e c i a l standards implemented during the course of the permit proceeding. Since a l l of these wastes are s p e c i f i c a l l y i d e n t i f i e d as candidates for being banned from land disposal i n two years under the Hazardous and Solid Waste Amendment (HSWA) (see also RCRA-amended Section 3004 (e) and (h)(4)), EPA proposed an interim regulatory regime for their land disposal (9). This rule became f i n a l on November 8, 1986, and, as a r e s u l t , wastes i d e n t i f i e d by the hazardous waste codes F020, F021, F022, F023, F026, F027, and F028 must be treated to a l e v e l below 1 ppb i n the waste extract for each of the following s p e c i f i c categories of CDDs and CDFs: TCDD—tetrachlorodibenzo-p-dioxins TCDF—tetrachlorodibenzofurans PeCDD—pentachlorodibenzo-p-dioxins PeCDF—pentachlorodibenzofurans HxCDD—hexachlorodibenzo-p-dioxins HxCDF—hexachlorodibenzofurans One ppb i s the routinely achievable detection l i m i t using method 8280 of SW-846: Test Methods for Evaluating Solid Waste Physical/ Chemical Methods (1982) (7_, Appendix X). (In test method 8280, the proposed q u a n t i f i c a t i o n l e v e l for 2,3,7,8-TCDD i n water i s 10 ppt. However, due to the interferences inherent i n leachate samples and the v a r i a b i l i t y of waste matrices, EPA considers that, generally, CDD wastes subject to this rule w i l l have a detection l i m i t of 1 ppb. I t should be noted that because the treatment standard for CDDs i s set at "no detection," i t i s important to c a l i b r a t e to the levels s p e c i f i e d i n method 8280. An interlaboratory v a l i d a t i o n of the method has recently been conducted and reported (10).) These l i s t e d wastes also must be treated below detection l i m i t s for 2,4,5-trichlorophenol, 2,4,6-trichlorophenol, 2,3,4,6tetrachlorophenol, and pentachlorophenol. The detection l i m i t s for these constituents are 50, 50, 100, and 10 ppb, respectively, i n the waste extracts using methods 3510/8270 i d e n t i f i e d i n SW-846. EPA also i s granting the maximum two-year variance to the e f f e c t i v e date of the land disposal r e s t r i c t i o n s ( 9 ) for dioxincontaining wastes because of a finding that there i s a lack of capacity to treat and dispose of these wastes. Thus, the e f f e c t i v e date of t h i s f i n a l rule i s November 8, 1988. Literature Cited 1.

U.S. Environmental Protection Agency (1983). Washington, DC, November 28.

Dioxin

Strategy.

2.

B e l l i n , J.S. and Barnes, D.G. (1985). Procedures for estimating risks associated with exposures to mixtures of chlorinated dibenzodioxins and -dibenzofurans (CDDs


3. DES ROSIERS

National Dioxin Study 53


and CDFs). Adopted by the Risk Assessment U.S. EPA, Washington, DC, November 21.

Forum,

3.

U.S. Environmental Protection Agency (1986). National Dioxin Strategy, Tier 1 and 2 Accomplishments. Draft Technical Support Document. Office of Solid Waste and Emergency Response, Washington, DC, January.

4.

des Rosiers, P.E. (1985). Methodologies for materials contaminated with PCDDs and related compounds. Paper presented at the 5th International Symposium on Chlorinated Dioxins and Related Compounds, Bayreuth, Federal Republic of Germany, September 16-19.

5.

U.S. Environmental Protection Agency (1986). The National Dioxin Study, Tiers 3, 5, 6, and 7. Draft F i n a l Report. Office of Water Regulations and Standards, Washington, DC, April.

6.

U.S. Environmental Protection Agency (1986). National Dioxin Study, Tier 4--Combustion Sources. Draft Project Summary Report. Office of A i r Quality Planning and Standards, Research Triangle Park, NC, A p r i l .

7.

U.S. Federal Register (1985), 50 (9), 1978-2006.

8.

des Rosiers, P.E., Westfall, B., Campbell, B. and Lee, A. (1986). PCB f i r e s : preliminary correlation of chlorobenzene and PCB contents of the f l u i d with PCDF and PCDD contents of soot. In: Proceedings: 1985 EPRI PCB Seminar, EPRI CS/EA/EL-4480, Project 2028, March, 7-26--7-39.

9.

U.S. Federal Register (1986), 51 (9), 1602-1766.

10.

Ballard, J.M., Vonnahme, T.L., Nunn, N.J., Youngman, D.R. and B i l l e t s , Stephen (1986). Performance of RCRA Method 8280 for the analysis of dibenzo-p-dioxins and dibenzofurans i n hazardous waste samples. EPA/600/S4-86/021, July.

RECEIVED December 10,

1986


National Dioxin Study - ACS Publications - American Chemical Society

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