The transgenic brackish medaka fish strain developed by City University have gone on show at the Science Museum.

The Transgenic Fish for Rapid Monitoring of Estrogenic Pollution exhibition, which runs until July 11, features the fish developed by the university's biology and chemistry department.

The fish can sensitively detect the presence of estrogenic endocrine disruptors and produce varying intensities of green fluorescence to reflect the estrogenic activity level.

Endocrine disruptors, also called environmental hormones, are exogenous substances that alter the functions of the endocrine system and consequently affect an intact organism, or its progeny, or populations.

Such disruptors include natural hormones, and man-made hormones and chemicals present in agriculture and everyday products, which can enter the human body through ingestion, inhalation or skin contact.

Adverse effects from these disruptors range from developmental malformation, reproductive organ tissue abnormality and cancer, to precocious puberty, obesity, poor semen quality, infertility, and social problems like a skewed sex ratio.

The university's technique can be extended to monitoring the estrogenic activity of the Pearl River and Hong Kong coastal waters in future.

The idea to use transgenic fish to monitor estrogenic pollutants can be applied to develop other transgenic organisms to monitor other kinds of pollutants such as androgenic endocrine disruptors, heavy metals and toxins.