Phthalates

Introduction

Characteristic of the Agent

Fate and Transport

Environmental Impacts

Environmental Monitoring

Exposure Pathway

Routes of Exposure

Methods for Measuring Human Exposure

Strategies for Preventing or Controlling Exposures


Harmful Effects

Dose Response

Absorption, Distribution and Metabolism

Biomarkers

Target Organs and Tissues

Mechanisms of Toxicity

Risk Assessment and Risk Management

References

5103/5104 Home

Fate and Transport

Aquatic Environments:

DBP and DEHP residues have been found in fish, water, and sediment, however, these phthalates do not bioaccumulate. IV The major sources of phthalates in waterways are from municipal and industrial effluents. Phthalic acid esters (PAE’s) can absorb to particulate matter in the stream and be deposited in the streambed. I DBP and DEHP can bind with fulvic acid, a chemical found in humic substance in soil and water because of the phthalate-fulvic acid is water soluble it can quickly move the insoluble PAE in aquatic ecosystems. I DEP under aerobic conditions will have a half live of 2 days to 2 weeks in aquatic systems but if absorbed onto suspended particles can exist in the soil sediment for over a century. V DBP, DEHP, and DEP have all been found in city drinking water in both surface and groundwater systems in low levels.

In fish, it is important to look not only at the exposure to a specific phthalate but to look at the major degradation products: monesters and phthalic acid. Chronic exposure (ingestion) of fish to DBP concentrations in fish above 90 ug per liter may be detrimental to human health. I Phthalates, which are rapidly metabolized, do not readily bioaccumulate because environmental organisms can excrete them. V Thus, biomagnifications do not take place in the food chain. In addition, do to the high rate of absorption to particles in the aquatic environment, aquatic exposure is reduced. V

Soil:

DEP will go through aerobic biodegradation, however, substantial fate progression will not occur through oxidation, chemical hydrolysis, and volatilization from wet soil surface but may volatize from dry soil. VI DEP, DEHP, and DBP all readily undergo sorption to soil particles.

Air:

If DEP is emitted or volatized into the air, it can exist as a vapor or absorb to particulates and through precipitation events can be washed out of the atmosphere and then be transported to aquatic or soil ecosystems. VI The primary degradation of phthalates in the atmosphere is through photodegradation with predicted half-lives of 0.2 to 4 days. V