Sodium perchlorate

Monitoring data

Administrative data

Endpoint:

monitoring data

Type of information:

experimental study

Adequacy of study:

other information

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

other: see 'Remark'

Remarks:

Site-related uncetainties: samples representing a snapshot in time and do not document the occurence of perchlorate under any climatic conditions. Results not standardized for meteorological conditions. Sample locations chosen for ease of sampling and not for perchlorate occurence . Biological samples varied in terms of number and type. All potential sources of perchlorate contamination are not identified. Biological/ecological uncertainties: routes of exposure to each receptor not evaluated. No gut analysis to evaluate food chain exposure. Analytical uncertainties: Detection limits for tissues higher than physical media samples. Laboratory procedures may afefct detection limits. Such kind of study cannot be standardized as many factors (biotic and abiotic) can interfere in the interpretation. Nevertheless, it allows to complete the global understanding in terms of perchlorate compartimentation in the environment and does not intend to represent all possible cases.

Data source

Reference

Reference Type:

other company data

Title:

Unnamed

Year:

2001

Materials and methods

Test guideline

Qualifier:

no guideline followed

Principles of method if other than guideline:

In order to determine the concentration of perchlorate in soil, sediment, plant tissue and animal tissue, the development of analytical methods to measure perchlorate in these media was required. Part of this investigation included the development of these methods. All analytical methods were based on USEPA's method 314.0 for perchlorate in water, and required the development of different extraction procedures for various biological media. All methods were successfully developped and verified for use in this study.

GLP compliance:

no

Type of measurement:

other: Six sites from throughout the United States were selected for this study. The sites were chosen to include diverse soil types and climatic conditions.

Media:

other: Water, soil, sediment, animals and plants.

Test material

Test material information

Constituent 1

Reference substance name:

Sodium perchlorate

EC Number:

231-511-9

EC Name:

Sodium perchlorate

Cas Number:

7601-89-0

Molecular formula:

ClHO4.Na

IUPAC Name:

sodium perchlorate

Study design

Details on sampling:

Since this project was to document the occurrence of perchlorate at the six sites, and not to develop bioaccumulation factors, the project goal for species selection was to collect representative samples from as many different matrices and biological groups as possible. The number and types of samples collected were dependent upon species availability at each of the sample locations, state and federal scientific collection permit limitations, and field personnel safety. All sample collection methods were performed in ways to minimize impact to local animal and plant populations. This study did not attempt to isolate perchlorate to particular body parts or plant tissue. All animals collected were analyzed as discrete samples from aliquots extracted from the whole body composite of each discrete animal unless a field composite of small animals (i.e., minnows) was necessary to provide the required volume for the analytical method to be successful.

A wide assortment of collection methods were necessary to obtain the abiotic and biotic media samples for this project. Over 960 samples were collected, and this section provides a brief description of the methods which were employed during the sampling efforts. Table 2.5 summarizes the procedures for sample collection, handling, and shipping. The following subsections provide more specific information on sampling methods for each sample medium. The workplan (Parsons, 2000) provides further detail on sample collection methods and health and safety issues for the investigation. In general, it was not possible to precisely co-locate samples (e.g. soli and animal tissue samples). However, samples were generally co-located within a sampling location based on the ease of sample collected and the presence of biological media.

Soil samples were collected directly into a sample container or with a trowel from approximately the top 3 inches of the soil column.

Discrete surface water samples were collected from approximately 1 foot below water surface using a dipper (when water depth permitted) and placed directly into the sample container. Samples were collected in a manner that ensured undisturbed conditions at the point of sampling (sample collected upstream of path walked to sample location and collected facing upstream). Surface water measurements (pH, dissolved oxygen, conductivity, and temperature) were collected in the same manner, after collection of the laboratory sample.

Discrete sediment grab samples were collected from the top '/2-inch to 1-inch of sediment in the water body and placed directly into the sample container. Typically three discrete samples were collected from the water body so a representative sample of the entire water body was obtained.

In addition to analyzing the sediment, analysis was performed on the interstitial water (pore water) which the laboratory decanted from the sediment preparation on approximately 10 percent of the sediment samples. The goal of this additional analysis was to determine if perchlorate concentrations differ in surface water, pore water, and in the sediment layer.

Discrete aquatic vegetation samples were collected by hand or with a dip net.

Dip nets and hand picking were used to collect aquatic invertebrates from the water body, man-made structures, and snags. Attempts were made to collect an appropriate mass of the same species for each sample.

Fish collection was performed by hand net, rod and reel, traps, and electroshocking. Due to personnel safety concerns, attempts were made to minimize electroshocking use. All fish not retained as samples were released at the point of capture.

Amphibians were collected by hand and dip net.

Waterfowl were shot with a 20 gauge shotgun with steel or bismuth shot. 2.2.2.10 Terrestrial Vegetation

Terrestrial vegetation was collected by hand. Sample collection was directed at the vegetation parts which were most likely consumed by the biota in the area (typically leaves, seeds and flowering stalks, when available).

Terrestrial insects were collected using sweep nets during the day and light traps (with sheet) and blacklights at night.

Reptile collection was performed by hand or through the use of nets or traps.

Birds were shot with a 12 or 20 gauge shotgun with steel or bismuth shot. 2.2.2.14 Mammals

Sherman live-capture traps were used for small mammal collection (e.g. mice). Bait typically consisted of oatmeal rolled with peanut butter. Removal of mammals from traps was performed by shaking the trap into a zip lock bag. After identification, target specimens were euthanized. Non target and surplus animals were released at the point of capture.

Larger mammals (e.g. cottontails) were shot with a 12 or 20 gauge shotgun with steel or bismuth shot, or with larger live traps. Bats were also collected with a 12 or 20 gauge shotgun. Attempts were made to capture bats using mist nets; however, none were captured by this method.

Special health and safety precautions were taken for field sampling team members, sample shipping, and laboratory personnel dealing with mammals which had the potential for transmitting diseases such as rabies or hantavirus. These procedures are discussed in detail in the workplan (Parsons, 2000).

Results and discussion

Details on results:

Results are summarized in the table included hereafter

Any other information on results incl. tables

Results were obtained for samples collected from each of the six perchlorate study sites: Yuma, Arizona (Yuma), Lake Mead NRA (Lake Mead Area), Allegany Ballistics Laboratory (ABL), Holloman Air Force Base (Holloman), Indian Head Area (Indian Head), and Longhorn Army Ammunition Plant (LHAAP).

All perchlorate results and reporting limits for analytical samples have been adjusted to "wet weight" values. The wet weight of a sample is obtained by multiplying the dry weight perchlorate concentration of the sample by [1 - (% moisture of the sample/100)].

To aid in the management and interpretation of the analytical data, adjusted analytical results for all samples collected at each of the six sites mentioned above are grouped by site, location and media (i.e. surface water, sediment, vegetation, fish, birds, invertebrates, etc.). Two different mean concentrations were calculated within each site specific media group to obtain representative perchlorate concentrations. The first mean concentration was the "mean for all samples." To calculate this mean, the perchlorate concentrations from all samples were used. For samples where perchlorate concentrations were not detected above the laboratory RL, the laboratory RL, rather than zero, was used in the calculation of the mean value. The other mean concentration was the "mean for detected samples." This procedure calculates a mean using only the samples that had perchlorate concentrations detected, excluding the nondetected samples. The use of both of these procedures allows for different ways of evaluating the data.

When a field duplicate contained a higher perchlorate concentration than the normal/parent sample, the field duplicate, with the higher perchlorate concentration, was used to calculate the media specific mean perchlorate concentration. The mean perchlorate concentrations are used in graphical representations within this section to simplify the large quantity of species-specific analytical data collected as part of this investigation and aid in the interpretation of potential perchlorate biotransport pathways.

Sites and media specific perchlorate concentrations; Vales are expressed in µg/L or µg/kg.

	Yuma, AZ		Lake mead area		Allegany ballistics laboratory		Holloman Air Force Base		Indian Head area		Longhorn Army Ammunition Plant
	N° of samples	Mean of all results	N° of samples	Mean of all results	N° of samples	Mean of all results	N° of samples	Mean of all results	N° of samples	Mean of all results	N° of samples	Mean of all results
Aquatic bird	1	400	8	397	--	--	--	--	--	--	--	--
Fish	7	396	19	2910	12	406	9	399	32	401	28	397
Amphibian	2	421	6	402	2	410	--	--	6	415	6	934
Aquatic vegetation	11	377	9	47900	12	397	3	407	6	325	9	4250
Pore water	2	3.0	2	49100	2	18.5	1	400	2	4.0	1	4.0
Sediment	17	81	16	16800	15	84.2	15	131	18	133	12	103
Surface water	24	4.18	23	37100	21	174	18	400	36	14.4	25	887
Soil	14	80.6	15	163000	27	1260	25	241	19	139	13	79.6
Terrestrial vegetation	27	553	33	69400	21	36000	57	666	21	423	18	905
Terrestrial insect	7	462	4	3120	13	1340	--	--	7	402	2	388
Terrestrial reptile	1	531	--	--	--	--	1	408	--	--	5	400
Terrestrial bird	9	398	7	1200	5	403	6	403	3	399	12	401
Terrestrial mammal	18	403	18	12000	5	404	28	404	12	400	7	422
Aquatic invertebrates	--	--	2	389	--	--	--	--	5	407	2	401
Pore water - downstream	--	--	1	1000	--	--	--	--	--	--	--	--
Sediment - downstream	--	--	6	4220	--	--	--	--	--	--	--	--
Surface water - downstream	--	--	6	13300	--	--	--	--	--	--	--	--
Terrestrail invertebrate	--	--	--	--	4	503	--	--	3	401	--	--
Groundwater	--	--	--	--	--	--	19	11.7	--	--	--	--
Aquatic reptile	--	--	--	--	--	--	--	--	7	396	3	397
Aquatic insect	--	--	--	--	--	--	--	--	1	398	3	741

Applicant's summary and conclusion

Conclusions:

The goal of this investigation was to document the occurrence of perchlorate in physical and biological media at six perchlorate contaminated sites across the United States representing different perchlorate levels and different climatic conditions. This goal was accomplished in that perchlorate was identified in numerous media at the sites. The present investigation provides new information on the presence of perchlorate in the environment.

Executive summary:

The goal of this investigation was to document the occurrence of perchlorate in physical and biological media at six perchlorate contaminated sites across the United States representing different perchlorate levels and different climatic conditions. This goal was accomplished in that perchlorate was identified in numerous media at the sites. The present investigation provides new information on the presence of perchlorate in the environment.

In addition, it can be concluded:

- Uptake of perchlorate occurs into various biological media,

- Both terrestrial and aquatic vegetation have the highest perchlorate concentrations and frequency of detection of all the media sampled at the sites investigated,

- There is an apparent correlation between surface water perchlorate concentrations and concentrations in other media, and

- Preliminary investigation of sait cedar leaf, seed, and leaf lifter show that different parts of the plant accumulate different levels of perchlorate.

While it is apparent that perchlorate is available for uptake by plants and animals, this study does not address the mechanism for the uptake of perchlorate from the environment. Overall, it appears that this study successfully documented the occurrence of perchlorate in the environment.

The following are recommendations for additional investigations that may supplement the information in this report and provide a better understanding of perchlorate in the environment.

- Perform additional field sampling of similar media at the sites and locations with high perchlorate concentrations and good species diversity. This could include specific co-location of samples collected, performance of field stomach content analysis of collected animais with follow-up sampling of the food sources identified, and organ specific analysis to determine specific tissue location of stored perchlorate. In addition, this study could be designed to address potential seasonal effects.

- Conduct inter-laboratory investigations on sample preparation procedures for biological media to improve reproducibility and documentation of steps to get from field sample to analytical extract.

- Perform an investigation on agricultural crops irrigated with water containing perchlorate to determine the possible occurrence of perchlorate in the crops.

- Determination of a water quality standard for perchlorate using microcosm studies on biological species in conjunction with existing environmental effects data.