Ornamental plants on sale to the public are a significant source of pesticide residues with implications for the health of pollinating insects.

Garden centres frequently market nectar- and pollen-rich ornamental plants as "pollinator-friendly", however these plants are often treated with pesticides during their production. There is little information on the nature of pesticide residues present at the point of purchase and whether these plants may actually pose a threat to, rather than benefit, the health of pollinating insects. Using mass spectrometry analyses, this study screened leaves from 29 different 'bee-friendly' plants for 8 insecticides and 16 fungicides commonly used in ornamental production. Only two plants (a Narcissus and a Salvia variety) did not contain any pesticide and 23 plants contained more than one pesticide, with some species containing mixtures of 7 (Ageratum houstonianum) and 10 (Erica carnea) different agrochemicals. Neonicotinoid insecticides were detected in more than 70% of the analysed plants, and chlorpyrifos and pyrethroid insecticides were found in 10% and 7% of plants respectively. Boscalid, spiroxamine and DMI-fungicides were detected in 40% of plants. Pollen samples collected from 18 different plants contained a total of 13 different pesticides. Systemic compounds were detected in pollen samples at similar concentrations to those in leaves. However, some contact (chlorpyrifos) and localised penetrant pesticides (iprodione, pyroclastrobin and prochloraz) were also detected in pollen, likely arising from direct contamination during spraying. The neonicotinoids thiamethoxam, clothianidin and imidacloprid and the organophosphate chlorpyrifos were present in pollen at concentrations between 6.9 and 81 ng/g and at levels that overlap with those known to cause harm to bees. The net effect on pollinators of buying plants that are a rich source of forage for them but simultaneously risk exposing them to a cocktail of pesticides is not clear. Gardeners who wish to gain the benefits without the risks should seek uncontaminated plants by growing their own from seed, plant-swapping or by buying plants from an organic nursery.

Prevalence of bottled water usage by pediatric dental patients: implications for dental health.

Drinking bottled water has become a popular substitute for tap water because of the concern over the contamination of municipal water supplies. The purpose of this study was to determine the percentage of pediatric dental patients drinking bottled water as their primary source of water. The fluoride content of these products was obtained from the distributors and the products were independently analyzed to ensure accuracy. Approximately 10 percent of 1,126 randomly selected patients from a private pediatric dental practice were routinely using bottled water from nine different sources. The fluoride content of these products varied from 0.04 ppm to 1.4 ppm. Independent analysis of the fluoride content of the different brands of bottled water using a microanalyzer with a fluoride-specific electrode indicated that the measured fluoride content was within +/- 0.1 ppm of the distributors' reported fluoride levels. The results of this study found that 16.9 percent of the pediatric patients were receiving less than the optimal level of fluoride and 72.4 percent were receiving greater than the recommended level of fluoride. Ten percent of the patients were being supplemented with additional fluoride tablets by their pediatrician, although the fluoride levels in the bottled water ranged from 0.9 to 1.4 ppm. In order for children to receive the optimal caries-preventive benefit from fluoride, the pediatric dentist needs to question the source of the patients' drinking water routinely. When bottled water is being used, the fluoride content should be obtained from the distributor or submitted for laboratory evaluation for fluoride content.