Benchmark values are derived from established drinking water standards for compounds grouped in Tier 1, from literature toxicological data for compounds in Tier 2, and from a Threshold of Toxicological Concern approach for compounds in Tier 3. A risk quotient is estimated by comparing the maximum concentration levels reported in greywater to the benchmark values.
The hazard quotient indices estimated with the use of central values of PDF(Cu) I, PDF(Cu) II, PDF(Ni) I and PDF(Ni) II log-normal distributions were: 0.013, 0.26, 0.0055 and 0.018, respectively (HQ < 1 — no essential human health risk can be expected).
Taking the quotient of estimated TCA + TCOH excreted to the upper bound of GSH conjugates excreted gives a lower bound on this excretion ratio of 360 540 to 1, which is indeed lower than and hence consistent with the estimated excretion ratio of 3,300 7,200 to 1 reported by Bernauer et al. (1996).
The generalized linear model (GLM) approach is particularly appealing since the parameters of interest (in our application the location quotients) are estimated directly along with confidence intervals and significance levels.
Participants were generally well educated (years of education: M=15.8, SD=3.1), had high estimated verbal intelligence quotient (VIQ: M=120.8, SD=9.3 estimated from the American National Adult Reading Test) (Ryan and Paolo, 1992), and high socioeconomic status (M=28.0, SD=14.7; the scale ranges from 11 to 77 with lower scores indicating higher SES) (Hollingshead, 1957).
Using the map with time step T, maps with time steps T/2, T/4, …, are found; ultimately, when the time step has become small enough, difference quotients furnish good estimates of the derivatives of the states.
HQ = Hazard quotient, EADI = Estimated Average Daily Intake.
DEE was calculated by the Weir's equation [26] using a food quotient of 0.823 estimated from the animal's diet.
Exclusion criteria were current, or a history of, substance abuse, current or previous psychiatric diagnoses, colour blindness, intelligence quotient (IQ) as estimated using the Wechsler Adult Intelligence Scale-Revised Chinese Version (WAIS-RC) [ 29] below 80 (representing intellectual impairment), and history of diffuse brain damage.
Ishikawa (2004) and Nomura et al. (2011) used the Location Quotient (LQ) method, which estimates the net transaction between two areas by the relative advantage measures.4 Yamada (2013) developed the Gravity-RAS method, in which a gravity model was used to obtain initial values of the RAS iterations.
