Declining sex ratio in a first nation community

Area of Science:

• Environmental health
• Reproductive epidemiology
• Indigenous community health

Background:

• Aamjiwnaang First Nation community members reported concerns about a declining male birth ratio.
• The community is situated near significant petrochemical and chemical industrial operations in the Great Lakes St. Clair River Area of Concern.

Purpose of the Study:

• To assess the trend in the sex ratio (proportion of male births) within the Aamjiwnaang First Nation from 1984-2003.
• To investigate potential contributing factors, including environmental exposures, to observed changes in the sex ratio.

Main Methods:

• Community-based participatory research approach.
• Statistical analysis of live birth data from 1984-2003 to determine sex ratio trends.
• Consideration of the community's proximity to industrial facilities and potential chemical exposures.

Main Results:

• A statistically significant decline in the proportion of male births was observed from 1994-2003 (m = 0.412, p = 0.008).
• The most pronounced decrease occurred in the most recent 5-year period (1999-2003) (m = 0.348, p = 0.006).
• The sex ratio trended downwards from an apparently stable ratio prior to the early 1990s.

Conclusions:

• The declining sex ratio in the Aamjiwnaang First Nation is a significant finding requiring further study.
• Proximity to industrial activities and potential chemical exposures are plausible factors contributing to the observed decrease in male births.
• Ongoing community health surveys aim to gather more data on exposures and health outcomes.