The variables in sediment_data.csv describe the contaminant data in sediment used in the 2019 assessment of the UK's Clean Seas Environment Monitoring Programme. The column headers are:

seriesID
Description: timeseries identifier
Unit:
Type: categorical
Levels: 4491
Note: identifies the data (a station / contaminant combination) that were grouped together into a timeseries and modelled to assess status and trends

station
Description: station identifier
Unit:
Type: categorical
Levels: 110
Note: monitoring station – links to station information in sediment_stations.csv

year
Description: monitoring year
Unit:
Type: discrete
Range: 1999, 2018
Note: for some data suppliers, monitoring is in winter and e.g. sampling in December 2017 and January 2018 would be regarded as having come from the same monitoring year

date
Description: sampling date
Unit:
Type: discrete
Range: 1999-01-18, 2018-11-05
Note:

time
Description: sampling time
Unit:
Type: continuous
Range: 00:00:00, 23:59:00
Note:

latitude
Description: sampling latitude
Unit: decimal degrees
Type: continuous
Range: 49.97, 61.03
Note:

longitude
Description: sampling longitude
Unit: decimal degrees
Type: continuous
Range: -8.76, 2.52
Note:

depth
Description: depth of sediment sample
Unit: m
Type: continuous
Range: 0.01, 0.2
Note: all samples are surface sampled and this is the lowest depth sampled

sampleID
Description: sample identifier
Unit:
Type: categorical
Levels: 3749
Note:

matrix
Description: sample matrix
Unit:
Type: categorical
Levels: SED63, SEDTOT
Note: see ICES reference codes for MATRX

group
Description: contaminant group
Unit:
Type: categorical
Levels: BDE, CB, metal, organoMetal, PAH.alkylated, PAH.parent
Note:
BDE = polybrominated diphenyl ethers
CB = polychlorinated biphenyls
organoMetal = tributyltin and derivatives
PAH.alkylated = alkylated polycyclic aromatic hydrocarbons
PAH.parent = parent polycyclic aromatic hydrocarbons

determinand
Description: contaminant
Unit:
Type: categorical
Levels: 50
Note: see ICES reference codes for PARAM; data submitted as CHRTR have been relabelled as CHR

metoa
Description: method of chemical analysis
Unit:
Type: categorical
Levels: 16
Note: see ICES reference codes for METOA

concentration
Description: concentration of contaminant
Unit: see unit column
Type: continuous
Range: 0.0015, 15200
Note:

unit
Description: unit of the concentration measurement and its uncertainty
Unit:
Type: discrete
Levels: mg/kg dw, ug/kg dw
Note:

qflag
Description: less-than qualifier for the concentration measurement
Unit:
Type: categorical
Levels: "", "<", "D"
Notes:
"D" indicates the measurement is left-censored at the limit of detection; i.e. the measurement is below the limit of detection, but it is not known by how much; the limit of detection is given in the concentration column.
“<” indicates the measurement is left-censored by an unspecified censoring criterion (which could be the limit of detection); the value of the censoring criterion is given in the concentration column.
"” indicates a non-censored measurement

uncertainty
Description: uncertainty in the concentration measurement
Unit: see unit column
Type: continuous
Range: 0.0000035, 3049
Note: analytical uncertainty expressed as the standard deviation

normConc
Description: normalised concentration of contaminant
Unit: see unit column
Type: continuous
Range: 0.0047, 34034
Note: the concentration normalised to 5% aluminium (metals) or 2.5% organic carbon (organics); the normalisation process is explained here; some normalised concentrations are ‘missing’ because the normaliser (aluminium or organic carbon) concentration was not reported or because the uncertainty in the normalised concentration was greater than the normalised concentration

normConc.qflag
Description: less-than qualifier for the normalised measurement
Unit:
Type: categorical
Levels: "", "<", "D"
Note: see qflag

normConc.uncertainty
Description: uncertainty in the normalised measurement
Unit: see unit column
Type: continuous
Range: 0.0000099, 2794
Note: analytical uncertainty expressed as the standard deviation

AL
Description: aluminium concentration
Unit: %
Type: continuous
Range: 0.013, 48.2
Note: all values are above the limit of detection

AL.uncertainty
Description: uncertainty in the aluminium measurement
Unit: %
Type: continuous
Range: 0.0005, 5.49
Note: analytical uncertainty expressed as the standard deviation

CORG
Description: organic carbon concentration
Unit: %
Type: continuous
Range: 0.03, 9.2
Note:

CORG.qflag
Description: less-than qualifier for the organic carbon measurement
Unit:
Type: categorical
Levels: "", "<", "D"
Note: see qflag

CORG.uncertainty
Description: uncertainty in the organic carbon measurement
Unit: %
Type: continuous
Range: 0.003, 17.1
Note: analytical uncertainty expressed as the standard deviation

DRYWT
Description: dry weight of the sample
Unit: %
Type: continuous
Range: 8.33, 94.8
Note: all values are above the limit of detection

DRYWT.uncertainty
Description: uncertainty in the dry weight measurement
Unit: %
Type: continuous
Range: 0.036, 3.35
Note: analytical uncertainty expressed as the standard deviation