Ok so this is barely on topic, but...
So I discover we have an Elderflower plant in our front garden. I'd like to have a go at making some elderflower cordial because it's nice, so I have found a recipe and it's actually really easy.
The plant is about 4 meters from the road, which is a main residential road with traffic throughput of about 20 cars/minute peak? (maybe - I havn't actually counted) dropping to less than 1 car/min off peak.
Now I'm wondering about risk from pollutants in the flowers. The recipe calls for 30 elderflower heads which makes 6 pints. Given that this is then diluted will any pollutants in the plants be high enough concentration to be a health risk?
I remember as a kid being told not to eat berries from roadside because they were full of lead. Then I remembered that we only had unleaded petrol these days. Then I found an article saying that benzene is produced from burning unleaded fuel and it's highly carcinogenic. Does that sound right?
Given that I cycle 4 miles to work and back every day through traffic is the extra exposure of the eldeflower cordial going to be worth worrying about?