For 40 years, extensive studies have been conducted to study the effects of phthalates in the environment. Improved analytical techniques have enabled more reliable measurements in a very wide range of water, sediment, soil, plant and animal samples. These are being used to raise the quality of the on-going risk assessments by calibrating and improving the models used.
Phthalates are widely dispersed in the environment but only at very low levels as they are subject to relatively rapid photochemical and biological degradation. In addition, their levels are falling because of the increasing use of water treatment plants.
Phthalates do not accumulate in water
Most higher organisms (such as fish) are able to rapidly metabolise and break them down without apparent harm. Therefore, biomagnification up the food chain does not occur.
In addition, most phthalates at concentrations up to their limits of solubility in water do not exhibit acute or chronic toxicity to a variety of aquatic organisms. (1,2)
Phthalates do not enter the human food chain
It has been suggested that spreading municipal sewage sludge on agricultural land could lead to plants absorbing phthalates and as a consequence, enter the human food chain. However this subject has been comprehensively studied over the years and there is no evidence to suggest that phthalates can enter the human food chain in this way.
There are two points to bear in mind: the rates at which phthalates biodegrade in sewage sludge and soils; and the uptake of phthalates by plants from the ground. Phthalates are subject to both aerobic (in the presence of oxygen) and anaerobic (without oxygen) biodegradation. Several investigations illustrate how phthalates rapidly biodegrade when mixed in sewage sludge.
1. Rhodes, JE, Adams, WJ, Biddinger, GR, Robillard, KA and Gorsuch, JW, (1995), Env. Toxicol. and Chemistry, 14, 11, 1967.
2. Adams, WJ, Biddinger, GR, Robillard, KA and Gorsuch, JW, (1995), Env. Toxicol. and Chemistry, 14,9,1569.