hazard quotient


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hazard quotient

Abbreviation: HQ
A numerical ratio used to estimate whether a toxic exposure will prove harmful to an exposed person or ecosystem. The ratio is typically expressed as the measurable toxic exposure to a screening benchmark, such as the highest concentration of the toxicant known not to cause harm. An HQ greater than 1.0 is potentially toxic. An HQ less than 1.0 is not toxic, unless the toxic exposure is to multiple substances each with its own biological or ecological risk.
See also: quotient
References in periodicals archive ?
Note: LOAEL, Lowest Observed Adverse Effect Level; NOAEL, No Observed Adverse Effect Level; BMD, Benchmark Dose; HQ, Hazard Quotient; RfD, Reference Dose; I, Population Incidence.
Hazard quotient was less than one when all their pathways were summed up indicating the absence of potential metals hazard of chromium, zinc, cadmium, lead and nickel to human health through ingestion of Cucumis sativus fruit and soil by residents in Eket.
Noncancer health risk hazard quotients (HQ) for respondents with mean and 95th percentile consumption rates.
If the installed flooring does not cover the entire floor, the noncancer and cancer hazard quotients will be correspondingly lower (e.g., if only 50% of the total floor area is covered, the modeled concentrations will be one half of those presented).
TABLE 1 Hazard quotients associated with the formaldehyde emissions from Lumber Liquidators' laminate flooring made in China.
The study is based on Target Hazard Quotients (THQs), formula-derived measurements which provide an indication of risk based on known safe dose limits.
For both the direct and indirect exposures, we calculated the hazard quotients as the ratio of the calculated exposures to both cancer and non-cancer health exposure guidelines.
For both the direct and indirect exposures, we calculated the hazard quotients as the ratio of the calculated exposures to the cancer (NSRL) and non-cancer (CREL) health exposure guidelines.
Table 2 summarizes the hazard quotients associated with the direct exposures of e-cigarette users and the indirect (passive) exposures of non-users.
With respect to the NSRL hazard quotients for cancer related health effects, four of the nine chemicals analyzed exceeded 1.0 for the direct exposure to users; lead (1.33), formaldehyde (1.64), NNK (2.36), and cadmium (5.13).
If we use the minimum rather than the maximum chemical emissions in Table 1, the modeled direct and indirect CREL hazard quotients still exceed 1.0 for propylene glycol (293 direct and 7.0 indirect) and nicotine (65 direct and 1.6 indirect).