Volatile organic compounds in human milk: methods and measurements

Area of Science:

• Environmental Health
• Analytical Chemistry
• Toxicology

Background:

• Volatile organic compounds (VOCs) are common indoor air pollutants.
• Human milk can potentially contain VOCs, posing exposure risks to infants.
• Accurate measurement methods for VOCs in human milk are crucial for risk assessment.

Purpose of the Study:

• To optimize headspace solid-phase microextraction (HS-SPME) methods for measuring VOCs in human milk.
• To assess preliminary levels of specific VOCs (MTBE, chloroform, benzene, toluene) in human milk.
• To compare infant exposure doses from inhalation of indoor air versus ingestion of human milk.

Main Methods:

• Optimized HS-SPME for VOC extraction from human milk samples.
• Analyzed milk from a North Carolina milk bank (n=5) and Baltimore women (n=8).
• Measured concurrent indoor air VOC concentrations using active sampling and GC/MS/SIM in Baltimore households.

Main Results:

• Median VOC concentrations in Baltimore human milk: MTBE (0.09 ng/mL), chloroform (0.55 ng/mL), benzene (0.12 ng/mL), toluene (0.46 ng/mL).
• Milk VOC levels correlated with indoor air concentrations for benzene, toluene, and MTBE.
• Infant daily dose from inhalation exceeded ingestion by 25-135 fold.

Conclusions:

• Indoor air inhalation is the dominant exposure pathway for VOCs in infants.
• Strategies to reduce infant VOC exposure should prioritize mitigating indoor air contamination.
• Optimized HS-SPME methods provide reliable VOC measurements in human milk for future research.