Researchers have suggested guidance in the United Kingdom should be revised because it does not recognize how lead is stored in soil and transferred to vegetables. Recent years have seen a rise in popularity of people growing their own fruit and vegetables, but many urban allotments have soil with lead levels above U.K. guidance values.
The study, published in the journal “Environment International”, highlighted suitability of certain crops for growing at sites with elevated lead such as shrub and tree fruit, whilst limiting consumption of selected root vegetables, such as rhubarb, beetroot, parsnips and carrots.
Variation of lead uptake in the different crops highlights a role for focusing on the types of crop grown as a way to mitigate any raised exposure. Management practices include keeping soil moist during dry periods and in windy conditions; peeling and thoroughly washing all crops, and hands, before eating.
The Environment Agency introduced guidelines in 2014 stating that 80 milligrams of lead per kilogram of soil was considered safe. Transfer of lead to humans can occur via direct exposure to soil and indirect exposure such as eating food containing lead and contaminated water.
Researchers said the guidelines should be revised depending on the type of soil and how tightly the lead is bound within it.