TIM Version 3.0 beta Technical Description and User Guide - Appendix C -Parameters used in TIM v3.0

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Appendix C. Parameters used in TIM v3.0
Symbol	Definition	Variable Type*	Units
A	Area of home range	Random	m²
AE_k	Assimilation efficiency for food item k	Random	none
A_rate	Application rate of pesticide	Constant	lb a.i./A
B	Length of in-field spray drift buffer	Constant	m
B_vol	Volume-based biotransfer factor; function of Henry’s law constant and Log Kow	Constant	µg/L fresh weight leaf/ μg/L air
BW	Body weight	Random	g/bird
C_{air(t)(drops)}	Pesticide concentration in a volume of air for the time step immediately following the pesticide application	Constant	μg/mL
C_air(t)(vol)	Concentration of the pesticide in air at time t (resulting from volatilization)	Random	μg/mL
CH	Height of crop	Constant	m
C_k(t)	Pesticide concentration on food item k at time t	Random	μg pesticide/g food
C_k(t=0)	Starting residue concentration on the day of application	Random	μg pesticide/g food
C_plant(t)	Concentration of the pesticide in crop foliage at time t	Random	mg/kg
C_w(dew)(t)	Concentration of dissolved pesticide in dew at time t	Random	μg/mL
C_w(puddle)(t)	Concentration of the pesticide in puddle at time t	Random	μg/mL
D	Fraction of hour where pesticide is applied	Constant	none
d	length of home range	Random	m
d1	portion of d that overlaps with the treated field	Random	m
d2	portion of d that is off of the treated field	Random	m
d3	distance between edge of treated field and edge of home range (that does not overlap with treated field)	Random	m
DAF	Dermal absorption fraction	Constant	none
D_contact(t)	Incidental Dermal Contact Dose	Random	μg pesticide/g-bw
D_dermal(t)	Dose through dermal exposure for a pesticide at time t	Random	μg pesticide/g-bw
D_dew(t)	Dose through drinking dew for a pesticide at time t	Random	μg pesticide/g-bw
D_diet(t)	Dose through diet for a pesticide at time t	Random	μg pesticide/g-bw
D_drinking(t)	Dose through drinking water for a pesticide at time t	Random	μg pesticide/g-bw
DF_k	Fraction of diet attributed to food item k	Constant	none
D_{inhalation(t)}	Dose through inhalation for a pesticide at time t	Random	μg pesticide/g-bw
D_intercept(t)	Intercepted Dermal Dose	Random	μg pesticide/g-bw
d_non-feeding	location of bird during non-feeding hours relative to edge of treated field	Random	m
DPR	Dislodgeable pesticide residues	Constant	mg/m²
d_soil	Depth of soil at equilibrium with water (in puddle)	Constant	cm
D_spray(t)	Droplet Inhalation Dose	Random	μg pesticide/g-bw
dt	distance from edge of field at time t	Random	m
D_total(t)	Dose from all exposure routes	Random	μg pesticide/g-bw
D_vapor(t)	Volatilization inhalation dose; function of pesticide concentration in air, volume of inhaled air, and body weight of the bird	Random	μg pesticide/g-bw
d_w	Depth of puddle water	Random	cm
DWIR	Drinking water intake rate	Random	mL/day
e	Base of natural logarithm (2.7182)	Constant	none
EEC_diet(t)	Estimated exposure concentration through diet for a pesticide at time t	Random	μg pesticide/g-bw
F_AM	Ratio of avian to mammalian pulmonary membrane diffusion rates from USEPA 2004	Constant	none
FC_k	Fraction of food that is contaminated	Constant	none
F_dfr	Dislodgeable foliar residue adjustment factor	Constant	kg/m²
F_field	Fraction of on field exposure	Random	none
FLUX_water	Total daily water ingestion rate	Random	mL/day
FMA	Food matrix adjustment factor	Constant	none
FMR	Free-living metabolic rate	Random	kcal/bird-day
f_oc(soil)	Fraction of organic carbon in soil	Constant	none
FOF	Frequency on field	Random	none
F_re	Avian route equivalency factor	Constant	none
F_red	dermal route equivalency factor	Constant	none
F_respired	Volumetric fraction of droplet spectrum not exceeding the upper size limit of respired particles for birds	Constant	none
F_retained	Fraction of pesticide that is retained in the bird from one time step to the next	Constant	none
FW_k	Fraction of water in fresh food item k	Constant	None
G	Gorging factor	Constant	None
GE_k	Gross energy for food item k	Random	kcal/g food
H	Henry’s law constant	Constant	atm/m³/mol
HF_(t)	Hourly fraction of total daily intake rate of food consumed at time t	Random	none
k	Food item	Constant	none
Koc	Organic carbon-water partition coefficient	Constant	mL/g OC
Kow	Octanol-water partition coefficient	Constant	none
LD₅₀	Lethal dose sufficient to kill 50% of exposed individuals	Constant	mg/kg
m_wax	Amount of wax per surface area of leaf cuticle	Constant	Ug/cm2
ME_k	Metabolizable energy for food item k	Random	kcal/g food
ME_total	Total metabolizable energy	Random	kcal/g food
M_pesticide	Pesticide concentration on the treated field at time t (accounting for dissipation); function of application rate	Random	mg
m_plant	Mass of plant per hectare	Constant	kg
m_wax	mass of wax per surface area of leaf cuticle	Constant	μg/cm²
n	Flock size	Constant	none
P₀₀	Probability that a bird, now off the field, will remain off the field in the next hour	Random	none
P₀₁	Probability that a bird, now off the field, will be on the field in the next hour	Random	none
P₁₀	Probability that a bird, now on the field, will be off the field in the next hour	Random	none
P₁₁	Probability that a bird, now on the field, will be on the field in the next hour	Random	none
P(x)	Probability of mortality to x birds	Constant	none
p	Fraction of total birds that died during simulation	Constant	none
Q	Fidelity factor	Constant	none
R	Universal gas constant (8.205 e^-5)	Constant	atm/m³/mol-K
r	degredation rate constant	Constant	hour^-1
R_{foliar contact}	Rate of foliar contact	Constant	cm²foliage/cm²body surface (per hour)
RH	height of spray release	Constant	m
r_k	Pesticide specific dissipation rate constant (for food item k)	Constant	hour^-1
R_rate	Respiration rate	Random	L/h
s	Mineau scaling factor	Constant	none
SA_total	Total surface area of bird	Random	cm²
S_F	Food ingestion scale factor	Random	none
S_I	Inhalation scale factor	Random	none
S_W	Water adjustment scale factor	Random	none
T	Air temperature	Constant	K
t	Time of simulation	Sequential value	hour
t_1/2k	Dissipation half-life for food item k	Constant	days
TDIR	Total daily intake rate	Random	g food/bird-day
T_mortality	Individual threshold for mortality	Random	μg pesticide/g-bw
TPR	Total pesticide residues	Constant	mg/kg
V_air	Volume of air in 1 ha to a height equal to the height of the crop canopy	Constant	L
V_inhalation	Volume of air respired	Random	L
water_food	Daily volume of water consumed by a bird through food	Random	mL/day
x	Number of dead birds (out of predetermined flock); used to determine probability	Constant	none
ε_t	Presence on-field, off-field parameter	Random	none
θ_soil	Porosity of soil	Constant	none
ρ_b	Bulk density of soil	Random	kg/L
ρ_p	density of soil particles	Constant	kg/L
ρ_water	density of water (1)	Constant	kg/L
ρ_plant	Density of the crop tissue assumed as fresh leaf	Constant	kg/L

^* "Constant" indicates that the parameter is set to one value. "Random" indicates that the parameter’s value varies based on a distribution of possible values.

TIM Version 3.0 beta Technical Description and User Guide - Appendix C -Parameters used in TIM v3.0

Pesticide Science and Assessing Pesticide Risks