Low risk posed by engineered and incidental nanoparticles in drinking water

Area of Science:

• Environmental Science
• Water Chemistry
• Nanotechnology

Background:

• Natural nanoparticles (NNPs) are ubiquitous in aquatic environments.
• Engineered nanoparticles (ENPs) are emerging environmental contaminants of concern.
• Understanding nanoparticle occurrence in water is crucial for risk assessment.

Purpose of the Study:

• To contrast the sources, composition, and occurrence of NNPs and ENPs in various water matrices.
• To evaluate the removal efficiency of ENPs during centralized drinking water treatment.
• To assess the potential risks associated with ENP and incidental nanoparticle exposure.

Main Methods:

• Review of existing literature on nanoparticle occurrence and detection in surface water, treated water, and tap water.
• Comparison of analytical challenges and concentrations of NNPs versus ENPs.
• Assessment of drinking water treatment plant efficacy in removing nanoparticles.
• Evaluation of nanoparticle release from distribution systems and premise plumbing.

Main Results:

• ENPs are significantly less abundant than NNPs in raw water sources.
• Conventional drinking water treatment plants are highly effective at removing both NNPs and ENPs.
• Tap water contains extremely low concentrations of ENPs, indicating a low ingestion risk.
• Incidental nanoparticles, arising from pipe corrosion, are a more significant concern in tap water than ENPs.

Conclusions:

• Current ENP levels in tap water pose a low risk to human health.
• The removal of ENPs by drinking water treatment plants is highly efficient.
• Future research should prioritize the occurrence and toxicity of incidental nanoparticles released from plumbing systems.