Data taken from US EPA (2015), p. 19 and 23.

NAFTA_SOP_Appendix_B
  NAFTA_SOP_Appendix_D

Format

2 datasets with observations on the following variables.

name

a factor containing the name of the observed variable

time

a numeric vector containing time points

value

a numeric vector containing concentrations

Source

NAFTA (2011) Guidance for evaluating and calculating degradation kinetics in environmental media. NAFTA Technical Working Group on Pesticides https://www.epa.gov/pesticide-science-and-assessing-pesticide-risks/guidance-evaluating-and-calculating-degradation accessed 2019-02-22

US EPA (2015) Standard Operating Procedure for Using the NAFTA Guidance to Calculate Representative Half-life Values and Characterizing Pesticide Degradation https://www.epa.gov/pesticide-science-and-assessing-pesticide-risks/standard-operating-procedure-using-nafta-guidance

Examples

  nafta_evaluation <- nafta(NAFTA_SOP_Appendix_D, cores = 1)
#> The SFO model is rejected as S_SFO is equal or higher than the critical value S_c
#> The representative half-life of the IORE model is longer than the one corresponding
#> to the terminal degradation rate found with the DFOP model.
#> The representative half-life obtained from the DFOP model may be used
  print(nafta_evaluation)
#> Sums of squares:
#>       SFO      IORE      DFOP 
#> 1378.6832  615.7730  517.8836 
#> 
#> Critical sum of squares for checking the SFO model:
#> [1] 717.4598
#> 
#> Parameters:
#> $SFO
#>          Estimate   Pr(>t)    Lower   Upper
#> parent_0  83.7558 1.80e-14 77.18268 90.3288
#> k_parent   0.0017 7.43e-05  0.00112  0.0026
#> sigma      8.7518 1.22e-05  5.64278 11.8608
#> 
#> $IORE
#>                Estimate Pr(>t)    Lower    Upper
#> parent_0       9.69e+01     NA 8.88e+01 1.05e+02
#> k__iore_parent 8.40e-14     NA 1.79e-18 3.94e-09
#> N_parent       6.68e+00     NA 4.19e+00 9.17e+00
#> sigma          5.85e+00     NA 3.76e+00 7.94e+00
#> 
#> $DFOP
#>          Estimate   Pr(>t)    Lower    Upper
#> parent_0 9.76e+01 1.94e-13 9.02e+01 1.05e+02
#> k1       4.24e-02 5.92e-03 2.03e-02 8.88e-02
#> k2       8.24e-04 6.48e-03 3.89e-04 1.75e-03
#> g        2.88e-01 2.47e-05 1.95e-01 4.03e-01
#> sigma    5.36e+00 2.22e-05 3.43e+00 7.30e+00
#> 
#> 
#> DTx values:
#>      DT50    DT90 DT50_rep
#> SFO   407    1350      407
#> IORE  541 5190000  1560000
#> DFOP  429    2380      841
#> 
#> Representative half-life:
#> [1] 841.41
  plot(nafta_evaluation)