Charity Transform has released a map showing needles reported across the city and there are a few surprising hotspots.

http://www.bristolpost.co.uk/news/bristol-news/map-shows-every-discarded-needle-44354

Inevitably, this is just the tip of the iceberg, and for every discarded needle reported to the Council many more exist, placing the public and cleansing staff at obvious risk.

This isn’t an answer, but it provides useful information and continues to raise awareness.