From a76221d87485029444c8e684022ca606a0c7e68d Mon Sep 17 00:00:00 2001 From: Johannes Ranke Date: Wed, 18 Jan 2017 22:41:01 +0100 Subject: Update static docs using pkgdown - Add _pkgdown.yml for a structured function/data reference - Make seealso links active - Make mkinfit calls quiet - Use pkgdown branch from pull request hadley/pkgdown#229 to have topics ordered --- docs/reference/PEC_soil.html | 229 +++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 229 insertions(+) create mode 100644 docs/reference/PEC_soil.html (limited to 'docs/reference/PEC_soil.html') diff --git a/docs/reference/PEC_soil.html b/docs/reference/PEC_soil.html new file mode 100644 index 0000000..0449f8e --- /dev/null +++ b/docs/reference/PEC_soil.html @@ -0,0 +1,229 @@ + + + + + + + + +Calculate predicted environmental concentrations in soil — PEC_soil • pfm + + + + + + + + + + + + + + + + + + + + + + + + +
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Calculate predicted environmental concentrations in soil

+
+ + +

This is a basic calculation of a contaminant concentration in bulk soil +based on complete, instantaneous mixing. If an interval is given, an +attempt is made at calculating a long term maximum concentration using +the concepts layed out for example in the PPR panel opinion (EFSA 2012).

+ + + 
PEC_soil(rate, rate_units = "g/ha", interception = 0, mixing_depth = 5,
+  PEC_units = "mg/kg", PEC_pw_units = "mg/L", interval = NA,
+  n_periods = Inf, tillage_depth = 20, chent = NA, DT50 = NA,
+  Koc = NA, Kom = Koc/1.724, t_avg = 0, scenarios = c("default",
+  "EFSA_2015"), porewater = FALSE)
+ +

Arguments

+
+
rate
+
Application rate in units specified below
+
rate_units
+
Defaults to g/ha
+
interception
+
The fraction of the application rate that does not reach the soil
+
mixing_depth
+
Mixing depth in cm
+
PEC_units
+
Requested units for the calculated PEC. Only mg/kg currently supported
+
PEC_pw_units
+
Only mg/L currently supported
+
interval
+
Period of the deeper mixing, defaults to 365, which is a year if +rate units are in days
+
n_periods
+
Number of periods to be considered for long term PEC calculations
+
tillage_depth
+
Periodic (see interval) deeper mixing in cm
+
chent
+
An optional chent object holding substance specific information. Can +also be a name for the substance as a character string
+
DT50
+
If specified, overrides soil DT50 endpoints from a chent object +If DT50 is not specified here and not available from the chent object, zero +degradation is assumed
+
Koc
+
If specified, overrides Koc endpoints from a chent object
+
Kom
+
Calculated from Koc by default, but can explicitly be specified +as Kom here
+
t_avg
+
Averaging times for time weighted average concentrations
+
scenarios
+
If this is 'default', the DT50 will be used without correction +and soil properties as specified in the REACH guidance (R.16, Table +R.16-9) are used for porewater PEC calculations. If this is "EFSA_2015", +the DT50 is taken to be a modelling half-life at 20°C and pF2 (for when +'chents' is specified, the DegT50 with destination 'PECgw' will be used), +and corrected using an Arrhenius activation energy of 65.4 kJ/mol. Also +model and scenario adjustment factors from the EFSA guidance are used.
+
porewater
+
Should equilibrium porewater concentrations be estimated +based on Kom and the organic carbon fraction of the soil instead of total +soil concentrations? Based on equation (7) given in the PPR panel opinion +(EFSA 2012, p. 24) and the scenarios specified in the EFSA guidance (2015, +p. 13).
+
+ +

Value

+ +

The predicted concentration in soil

+ +

Details

+ +

This assumes that the complete load to soil during the time specified by +'interval' (typically 365 days) is dosed at once. As in the PPR panel +opinion cited below (PPR panel 2012), only temperature correction using the +Arrhenius equation is performed.

+

Total soil and porewater PEC values for the scenarios as defined in the EFSA +guidance (2015, p. 13) can easily be calculated.

+ +

Note

+ +

If temperature information is available in the selected scenarios, as + e.g. in the EFSA scenarios, the DT50 for groundwater modelling + (destination 'PECgw') is taken from the chent object, otherwise the DT50 + with destination 'PECsoil'.

+ +

References

+ +

EFSA Panel on Plant Protection Products and their Residues (2012) + Scientific Opinion on the science behind the guidance for scenario + selection and scenario parameterisation for predicting environmental + concentrations of plant protection products in soil. EFSA Journal + 10(2) 2562, doi:10.2903/j.efsa.2012.2562

+

EFSA (European Food Safety Authority) (2015) EFSA guidance document for + predicting environmental concentrations of active substances of plant + protection products and transformation products of these active substances + in soil. EFSA Journal 13(4) 4093 + doi:10.2903/j.efsa.2015.4093

+ + +

Examples

+ 
PEC_soil(100, interception = 0.25)
#>      scenario
+#> t_avg default
+#>     0     0.1

+# This is example 1 starting at p. 79 of the EFSA guidance (2015)
+PEC_soil(1000, interval = 365, DT50 = 250, t_avg = c(0, 21),
+               scenarios = "EFSA_2015")
#>      scenario
+#> t_avg      CTN      CTC      CTS
+#>    0  21.96827 11.53750 9.145259
+#>    21 21.78517 11.40701 9.017370
PEC_soil(1000, interval = 365, DT50 = 250, t_av = c(0, 21),
+               Kom = 1000, scenarios = "EFSA_2015", porewater = TRUE)
#>      scenario
+#> t_avg       CLN       CLC       CLS
+#>    0  0.7589401 0.6674322 0.9147861
+#>    21 0.7506036 0.6590345 0.8987279

+# The following is from example 4 starting at p. 85 of the EFSA guidance (2015)
+# Metabolite M2
+# Calculate total and porewater soil concentrations for tier 1 scenarios
+# Relative molar mass is 100/300, formation fraction is 0.7 * 1
+results_pfm <- PEC_soil(100/300 * 0.7 * 1 * 1000, interval = 365, DT50 = 250, t_avg = c(0, 21),
+                        scenarios = "EFSA_2015")
+results_pfm_pw <- PEC_soil(100/300 * 0.7 * 1000, interval = 365, DT50 = 250, t_av = c(0, 21),
+                           Kom = 100, scenarios = "EFSA_2015", porewater = TRUE)
+
+ +
+ + +
+ + + -- cgit v1.2.1