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Table 3 Point of departure concentrations for selected endpoints used as input for deriving a human-health screening level. All studies report adverse effects in relation to polystyrene spheres of varying sizes, as summarized in Table 2

From: Development and application of a health-based framework for informing regulatory action in relation to exposure of microplastic particles in California drinking water

Study Endpoint Metric used for PODa NOAELb
(mg /kg-day)
LOAELb
(mg /kg-day)
Best-fit Modelc BMDS Recommendationd Scaled residual for dose group near BMD
(unitless)
Scaled residual for control dose group
(unitless)
BMDL
(mg /kg-day)
BMD
(mg /kg-day)
BMDU
(mg /kg-day)
Amereh et al. [1] Luteinizing hormone concentration LOAEL/10 NA 1 Hill Viable 0.17 0.17 NA NA NA
Amereh et al. [1] Follicle stimulating hormone concentration LOAEL/10 NA 1 Exponential 3 Questionable 7 × 10–5 3.99 NA NA NA
Amereh et al. [1] Testosterone concentration BMDL NA 1 Exponential 4 Viable 0.23 0.23 0.26 0.46 Infinity
Amereh et al. [1] Sperm count BMDL NA 1 Hill Viable 0.30 0.30 0.27 0.41 0.7
Amereh et al. [1] Sperm motility BMDL 1 3 Exponential 4 Viable -0.45 0.12 0.54 0.79 1.2
Amereh et al. [1] Sperm DNA damage BMDL 1 3 Polynomial Degree 3 Viable -1.02 0.49 0.67 0.82 1.2
Amereh et al. [1] Sperm maturity BMDL 1 3 Exponential 3 Viable 0.85 -0.20 0.78 0.97 1.6
Amereh et al. [1] Sperm viability BMDL NA 1 Polynomial Degree 3 Viable -0.85 1.01 0.85 1.0 1.4
Amereh et al. [1] Sperm Deformity BMDL 1 3 Polynomial Degree 3 Viable 0.89 -0.51 1.0 1.2 1.8
An et al. [3] Anti-Mullerian hormone concentration BMDL 0.015 0.15 Exponential 4 Viable 0.090 -0.077 0.14 0.20 0.32
Deng et al. [29] Liver Condition Index BMDL 2.6 13 Exponential 4 Viable -0.18 -0.57 0.68 2.5 39
Deng et al. [29] Liver Condition Index BMDL 2.6 13 Polynomial Degree 3 Viable -0.01 0.71 4.98 10 13
Hou et al. [47] Testis Weight LOAEL/10 NA 0.017 Exponential 3 Questionable 0.08 2.46 NA NA NA
Hou et al. [47] Sperm deformity NOAEL 0.17 1.7 Hill Questionable 7 × 10–6 0.74 NA NA NA
Hou et al. [48] Anti-Mullerian hormone concentration BMDL 0.083 0.83 Exponential 5 Viable -0.022 0.019 0.025 0.034 0.14
Li et al. [64] Sperm deformity NOAEL 0.83 8.3 Linear Questionable 1.46 -1.04 NA NA NA
Xie et al. [124] Body weight LOAEL/10 NA 0.43 Exponential 2 Questionable -0.02 0.42 NA NA NA
Xie et al. [124] Sperm count LOAEL/10 NA 0.43 Exponential 4 Questionable 0.77 1.79 NA NA NA
Xie et al. [124] Sperm deformity LOAEL/10 NA 0.43 Exponential 4 Questionable -0.28 -1.37 NA NA NA
Xie et al. [124] Testosterone concentration LOAEL/10 NA 0.43 Polynomial Degree 3 Questionable 0.13 2.07 NA NA NA
  1. NA Not Available
  2. aWhen viable BMD models were recommended by BMDS software, BMDs were used as the POD. If not, the NOAEL was used. When NOAELs were unavailable, the LOAEL was used with an UF of 10
  3. bStudies did not always explicitly refer to exposure concentrations as LOAELs and NOAELs and were often inferred from text and figures based on statistical relationships relative to control
  4. c Models selected for use met all of the default threshold criteria set by BMDS software, such as constant variance, goodness of fit, ratio of BMD/BMDL, absolute residual of controls and exposure, etc. and had the lowest Akaike’s Information Criteria of models tested (US EPA [36]). All models are based on a normal coefficient of variance
  5. dEPA’s BMDS software provides a recommendation for the viability of the best-fit model. When models were recommended as ‘viable’, BMDs were used. Otherwise, NOAELs or LOAELs were used as point-of-departures