Aging of Copper Nanoparticles in the Marine Environment Regulates Toxicity for a Coastal Phytoplankton Species.

Environmental conditions in aquatic ecosystems transform toxic chemicals over time, influencing their bioavailability and toxicity. Using an environmentally relevant methodology, we tested how exposure to seawater for 1-15 weeks influenced the accumulation and toxicity of copper nanoparticles (nano-Cu) in a marine phytoplankton species. Nano-Cu rapidly agglomerated in seawater and then decreased in size due to Cu dissolution. Dissolution rates declined during weeks 1-4 and remained low until 15 weeks, when the large agglomerates that had formed began to rapidly dissolve again. Marine phytoplankton species were exposed for 5-day periods to nano-Cu aged from 1 to 15 weeks at concentrations from 0.01 to 20 ppm. Toxicity to phytoplankton, measured as change in population growth rate, decreased significantly with particle aging from 0 to 4 weeks but increased substantially in the 15-week treatment due apparently to elevated Cu dissolution of reagglomerated particles. Results indicate that the transformation, fate, and toxicity of nano-Cu in marine ecosystems are influenced by a highly dynamic physicochemical aging process.

Naloxone availability in independent community pharmacies in Georgia, 2019.

BACKGROUND: Increasing the availability of naloxone among people who use opioids, and friends and family of past and present people who use opioids is a vitally important mission to reduce the occurrence of opioid-related overdose deaths. The purpose of this study was to determine the availability of naloxone in independent community pharmacies in Georgia. Secondary objectives include determining pharmacists' knowledge regarding the standing order and ability to counsel regarding naloxone. METHODS: A cross-sectional study using a secret shopper approach with phone contact was conducted over a period of 10 months. The study was population based and was conducted at all independent pharmacies in the state of Georgia. All independent community pharmacies in the state of Georgia were contacted and asked the naloxone questions with a 96% response rate (n = 520). RESULTS: Five hundred fifty-eight independent community pharmacies were called, with a 96% response rate (n = 520 pharmacies). Two hundred-twenty pharmacies reported having naloxone in stock. Of the 335 pharmacists asked, 174 (51.9%) incorrectly said that a prescription was required. The mean (SD) cash price was $148.02 (27.40), with a range of $0 to $300. Of 237 pharmacists asked who had naloxone in stock or who stated they could get naloxone in stock, 212 stated that they could demonstrate how to use it, 8 stated they could not, and 17 said that they possibly could or were unsure how to use it. CONCLUSIONS: This study provided insight into the limited availability of naloxone at independent community pharmacies in Georgia after the standing order was issued. The majority of pharmacists at independent pharmacies in Georgia were not using the publicly available state naloxone standing order. Additionally, the low availability of naloxone and its high cost for uninsured individuals are significant structural barriers for reducing opioid-related mortality.

Release and detection of nanosized copper from a commercial antifouling paint.

One major concern with the use of antifouling paints is the release of its biocides (mainly copper and zinc) into natural waters, where they may exhibit toxicity to non-target organisms. While many studies have quantified the release of biocides from antifouling paints, very little is known about the physicochemical state of released copper. For proper risk assessment of antifouling paints, characterization of copper released into water is necessary because the physicochemical state determines the metal's environmental fate and effects. In this study, we monitored release of different fractions of copper (dissolved, nano, and bulk) from a commercial copper-based antifouling paint. Release from painted wood and aluminum mini-bars that were submerged in natural waters was monitored for 180 days. Leachates contained both dissolved and particulate copper species. X-ray diffraction and X-ray photoelectron spectroscopy were used to determine the chemical phase of particles in the leachate. The amount of copper released was strongly dependent on water salinity, painted surface, and paint drying time. The presence of nanosized Cu2O particles was confirmed in paint and its leachate using single-particle inductively coupled plasma-mass spectrometry and electron microscopy. Toxicity of paint leachate to a marine phytoplankton was also evaluated.