Mae adroddiad data dros dro ar y 12 mis cyntaf ers cyflwyno'r terfyn cyflymder o 50mya, sy'n cael ei gyhoeddi ar ddydd Llun 7 Hydref, wedi dangos bod lefelau NO2 wedi gostwng ym mhob un o'r pum lleoliad.
An interim data report on the first 12 months of the 50mph speed limits being introduced, which is published on Monday 7 October, has shown a reduction in NO2 levels at all 5 locations.