Hobbyodlarens exponeringsrisk för kadmium och bly i bondbönor (Vicia faba)

Sammanfattning

A regular consumption of food contaminated with heavy metals can pose a threat to the general health of the human population. The contents of these toxic metals in crops depend on several different factors including the acidity of the soil as well as the addition of contaminated fertilizer. In this study, health risk assessments for broad beans (Vicia faba) were made for six different growing conditions, from the perspective of a hobby farmer. Hence, the seeds, soil and fertilizer were all bought in a local gardening shop. The water used to water the crops was of three various degrees of acidity representing tap water, natural rain and acidic rain. In each watering pair, one group received an addition of fertilizer. After almost seven weeks of growth the concentrations of the heavy metals cadmium and lead were measured in the flowers and roots of the bean plants. The values were compared to the allowed maximum concentrations in legumes intended for commercial distribution according to EU legislation. Calculations were made to assess how much the consumption of the beans would be compared to the tolerable daily intake of cadmium and lead. This study shows that hobby farmers consuming their home-grown broad beans are not especially at risk regarding cadmium exposure, nor are the concentrations exceeding limit values. However, concerning the lead exposure the result shows that there is a slightly higher risk in general. Certain growing conditions could in some cases result in exceeded limit values and major contributions to the total tolerable intake. Performing this kind of study is important in mapping hobby farmers’ exposure to heavy metals; a topic that is otherwise not included in any controls aimed at making sure the crops they grow are safe to eat.