id	keyword
american_scientific_journal-1581	metals
american_scientific_journal-1581	line
american_scientific_journal-1581	soil
american_scientific_journal-1581	vegetables
american_scientific_journal-1581	concentrations
american_scientific_journal-1581	spinach
american_scientific_journal-1581	lettuce
american_scientific_journal-1581	species
american_scientific_journal-1581	plant
american_scientific_journal-1581	carrot