GSTM1 and anemia (phenotype): The prevalence of anaemia among adolescent girls was 29%: 15% had mild anaemia (11 g/dl ≤ Hb < 12 g/dl; 11 g/dl ≤ Hb < 11.5 g/dl for girls 10–11 years), 13% had moderate anaemia (8 g/dl ≤ Hb < 11 g/dl), and 1% had severe anaemia (Hb < 8 g/dl).