Human toxicity potentials for life-cycle assessment and toxics release inventory risk screening

Area of Science:

• Environmental Chemistry
• Toxicology
• Life Cycle Assessment

Background:

• Human Toxicity Potential (HTP) is an index used to quantify the environmental harm of chemical emissions.
• HTP integrates inherent toxicity and potential dose for accurate risk assessment.
• It is crucial for weighting emissions in Life Cycle Assessment (LCA) and Toxics Release Inventory (TRI).

Purpose of the Study:

• To present Human Toxicity Potential (HTP) values for both cancer and non-cancer endpoints.
• To provide HTP values for 330 compounds emitted into air and surface water.
• To cover a significant portion (79%) of chemicals listed in the U.S. EPA's 1997 TRI data.

Main Methods:

• Calculated HTP based on inherent toxicity (cancer potency q1*, safe dose RfD/RfC) and potential dose.
• Utilized the CalTOX model to determine chemical distribution and exposure routes (inhalation, ingestion, dermal).
• Aggregated emissions using reference compounds like benzene (carcinogens) and toluene (noncarcinogens).

Main Results:

• Generated cancer and non-cancer HTP values for 330 distinct chemical compounds.
• The dataset includes 258 chemicals from the U.S. EPA TRI, representing 79% of reported air emissions in 1997.
• This provides a comprehensive resource for evaluating the human toxicity of common industrial chemicals.

Conclusions:

• The study provides essential HTP data for a wide range of chemicals, enhancing environmental impact assessments.
• These HTP values facilitate more accurate comparisons and aggregation of chemical emissions.
• The findings support improved environmental management and regulatory decision-making regarding chemical releases.