Infestations of parthenium weed can degrade natural ecosystems. The plant can produce serious allergenic reactions in humans. Parthenium aggressively colonises disturbed sites and has major impacts on pasture and cropping industries, spreading to and impacting on new
Outcompetes native species, in part due to allelopathy.
Location Specific Impacts:
Economic/Livelihoods: In Queensland, Australia, losses to the cattle industry have been estimated to be A$16 million per year in control costs and loss of pasture.
Ecosystem change: In Queensland, Parthenium has been shown to impact significantly on the biodiversity of the Einasleigh Uplands bioregion and the central highlands.
Human nuisance: Frequent contact with the plant or its pollen can produce serious
allergic reactions: dermatitis, hay fever and
Human nuisance: In India, an extensive outbreak of "weed dermatitis" caused by parthenium allergy, involving perhaps 1000 patients with some deaths has been observed (Richard J. Schmidt, 2004).