DOTS

BSAF

Biota-Sediment Accumulation Factor Database

US Army Corps of Engineers ERDC Dredging Operations Technical Support

USACE

About

The USACE has used bioaccumulation tests since the 1970s to make regulatory decisions regarding the management of dredged sediment. Prior to disposing of dredged sediment in ocean waters, the sediment must be evaluated to determine whether contaminants are present and whether the contaminant level may adversely impact the ecosystem at the ocean site. The USACE strives to protect human health and the environment by accurately identifying persistent, bioaccumulative, toxic substances and restricting disposal of these sediments. To help interpret data from these bioaccumulation tests, the USACE uses published BSAF data. To help meet the USACE need, the BSAF database was developed in the 1990s as a centralized repository of BSAF data. The database is a compilation of data, providing information on ratios between aquatic species and hydrophobic organic chemicals and organotin compounds. The source of data is primarily the peer-reviewed literature and reports submitted by U.S. government agencies. The database is updated annually with new records.

What is BSAF?

Biota-sediment accumulation factor (BSAF) is the ratio of the lipid-normalized concentration of a hydrophobic organic chemical (HOC) in an organism to the organic carbon-normalized concentration of the HOC in the sediment the organism was exposed to.

BSAF values are typically calculated using the following (or similar) formula:

bsaf

-the HOC concentration in the organism (wet or dry weight)
-the lipid concentration (fraction) in the organism (wet or dry weight)
-the HOC concentration in the sediment (generally dry weight)
-the total organic carbon content (fraction) of the sediment (generally dry weight)

HOCs preferentially partition to lipids so researchers commonly normalize concentrations of HOCs to lipid concentration in the tissue. This is accomplished by dividing tissue HOC concentration by lipid concentration to form lipid-normalized data. The concentration of total organic carbon (often referred to as TOC or OC) in sediment may also influence bioavailability because HOCs preferentially partition into the organic material in sediments because of the similar chemical nature of the organic material to the HOCs. Researchers normalize contaminants to sediment organic carbon by dividing the sediment contaminant concentration by the content of the sediment TOC.

In the past, sediment-based bioaccumulation factors were named accumulation factor, partitioning factor, bioavailability index and biota-sediment factor. All relate bioaccumulation to the concentration of a contaminant in the sediment. Due to inconsistency in naming, the term biota-sediment accumulation factor (BSAF) was proposed by Ankley et al. (1992). BSAFs have been used to both predict the amount of contaminant likely to be accumulated from sediment at equilibrium and for data comparison among species, compounds, sediment types, and contaminant concentrations.

Example

Example: Normalize the concentration of contaminant to lipid concentration in the tissue for an organism that has 308 ng PCB/g dry weight tissue with a lipid content of 8.4% dry weight (fraction= 0.084). Note the tissue concentration and lipid content must both be based on either wet weight or dry weight.

Lipid-normalized concentration: ex1 ex2

Example: Normalize the concentration of contaminants to sediment organic carbon for a sediment having 23 ng PCB/g dry weight and a mean TOC content of 2.8% TOC (fraction= 0.028)

Carbon-normalized concentration: ex3 ex4

 

ex5

Structure

BSAF data is provided with limited supporting information (see Table 1 below). We recommend you revisit the literature to confirm your findings. We acknowledge there are other types of information that may be of value to your search that are not reported here. If you are interested in additional BSAF supporting information, please e-mail your ideas to the database manager and we will consider incorporating them going forward (E-mail database manager).

Data Quality Objectives

Systematic searches are conducted using a variety of resources including in-house and public databases. For each identified paper, an electronic copy is obtained for evaluation. Studies meeting the minimum data quality objectives listed below are accepted:

  1. BSAF formula is defined as described above (i.e., BSAF is normalized).
  2. Exposure to a hydrophobic organic compound or organotin compound.
  3. Test species was a fish or other aquatic organism (e.g., bivalves, crabs).

Other supporting information is collected but is not required for acceptance. Note that studies do not report the same level of detail. As a result, some supporting data fields will contain no information. We make no attempt to assign value to a study. Users interested in learning more about criteria for selecting bioaccumulation numbers should see References and Other Readings for a starting point.

Table 1. Data fields and descriptions. Data fields are grouped by category (record, chemical, organism, sediment, experiment, etc.) to help sort fields.

Field Name Category Description
ID  Record  Unique identification number autogenerated by database 
Study  Record  Field Study, Laboratory Experiment, Mesocosm 
ChemName  Chemical  Name of chemical 
CAS  Chemical  A CAS is a unique numerical identifier assigned by the Chemical Abstract Service (CAS) 
GenusSpecies  Animal  Genus and species of animal 
Age  Animal  Age of animal 
WildCult  Animal  Animal collected in the wild or cultured 
OrgNote  Animal  Notes about animal; may include where the animal was collected/obtained and when 
SedType  Sediment  Sediment type: Natural-collected from field; Artificial-made in laboratory; Amended-collected from field and amended w/other substance (e.x. carbon); Natural, terrestrial- collected from a terrestrial location 
SedDepth  Sediment  depth (cm) of sediment collection (e.g., surficial sediment or 0-10 cm) 
SedWat  Sediment  water body the sediment was collected from 
SedYear  Sediment  the year sediment was collected 
SedTime  Sediment  the time of year sediment was collected (i.e., September, October, Fall, Winter) 
SedState  Sediment  the state where sediment was collected (applies to USA only) 
SedCntry  Sediment  the country where sediment was collected 
SedLndmrk  Sediment  if provided, the area where sediment was collected in a water body (i.e., harbor name, coordinates, area of lake) 
Spiked  Sediment  was the sediment spiked with a chemical? Yes or no (common in lab experiments) 
ExpDuration  Experiment  length of lab experiment (i.e., 28 days) 
ExpRatio  Experiment  the sediment to water ratio 
ExpNote  Experiment  may include information about feeding, purging, water exchange rates 
Organism  Concentration  If provided, tissue concentration normalized to lipid content; if information is available ERDC will calculate; all converted to ug/kg lipid 
Sed  Concentration  If provided, sediment concentration normalized to organic content; if information is available ERDC will calculate; all converted to ug/kg TOC 
Lipid  Lipid Fraction  Lipid content 
FlUnit  Lipid Fraction  units reported for lipid (i.e., % wet weight) 
Foc  Organic Carbon  total organic content (OC or TOC) 
FocUnit  Organic Carbon  unit reported for TOC; usually % dry weight 
SampleID  BSAF  table, figure, text, sampleID associated with BSAF number 
bsaf  BSAF  BSAF number; if tissue, sediment, lipid and TOC are provided ERDC will calculate to confirm BSAF 
bsafType  BSAF  summary type (i.e., mean, median, mode) 
bsafErr  BSAF  error 
bsafErrType  BSAF  error type (i.e., SD, SE) 
BSAF  Number of samples 
WetDry  BSAF  Based on wet weight only (e.g., tissue, lipid, sediment, & TOC all reported as wet weight) = W; or dry weight only = D; most common is wet (tissue & lipid ww)/dry(sediment & TOC) = W/D 
BSAFnotes  BSAF  Note about how BSAF was calculated 


References and other readings

Ankley, G.T., P.M. Cook, A.R. Carlson, D.J. Call, J.A. Swenson, H.F. Corcoran and R.A. Hoke. 1992. Bioaccumulation of PCBs from sediments by oligochaetes and fishes: comparison of laboratory and field studies. Canadian Journal of Fisheries and Aquatic Sciences 49:2080-2085.

Burkhard, L., P.M. Cook and M.T. Lukasewycz. 2005. Comparison of biota-sediment accumulation factors across ecosystems. Environmental Science and Technology 39: 5716-5721.

Judd, N., L. Tear and J. Toll. 2013. From sediment to tissue and tissue to sediment: an evaluation of statistical bioaccumulation models. Integrated Environmental Assessment and Management 10:102-113.

Klimisch, H.J., M. Andreae and U. Tillman. 1997. A systematic approach for evaluating the quality of experimental toxicology and ecotoxicology data. Regulatory Toxicology and Pharmacology 25: 1-5.

Parkerton, T.F., J.A. Arnot, A.V. Weisbord, C. Russom, R.A. Hoke, K. Woodburn, T. Traas, M. Bonnell, L.P. Burkhard and M.A. Lampi. 2008. Guidance for evaluating in vivo fish bioaccumulation data. Integrated Environmental Assessment and Management 4:139-155.

Van Geest, J. L., D.G. Poirier, P.K. Sibley and K.R. Solomon. 2010. Measuring bioaccumulation of contaminants from field-collected sediment in freshwater organisms: a critical review of laboratory methods. Environmental Toxicology and Chemistry 29:2391-2401.

Weisbrod, A.V. and 13 co-authors. 2007. Workgroup report: review of fish bioaccumulation databases used to identify persistent, bioaccumulative, toxic substances. Environmental Health Perspectives 115:255-261.