Adv Exp Med Biol
-
This paper reviews the rapidly expanding literature on the ecological effects of cyanobacterial toxins. The study employs a qualitative meta-analysis from the literature examining results from a large number of independent studies and extracts general patterns from the literature or signals contradictions. The meta-analysis is set up by putting together two large tables--embodying a large and representative part of the literature (see Appendix A). ⋯ The paper concludes by summarizing the risks for birds, fish, macroinvertebrates and zooplankton. Although acute (lethal) effects are mentioned in the literature, mass mortalities of--especially--fish are more likely to be the result of multiple stress factors that co-occur during cyanobacterial blooms. Bivalves appear remarkably resistant, whilst the harmful effects of cyanobacteria on zooplankton vary widely and the specific contribution of toxins is hard to evaluate.
-
The occurrence of toxic cyanobacterial blooms in Florida waters have become more prominent following increased growth, declining groundwater supplies, and identification of impaired surface waters as future drinking water sources. Cyanobacterial toxins have been identified in source waters used for drinking water supply and in post-treated drinking water during algal bloom events. Algal toxin concentrations in post-treated drinking water have exceeded existing and proposed World Health Organization guidelines for the oral consumption of microcystin and cylindrospermopsin. ⋯ Epidemiological studies may also be required in Florida to assess potential human health risks due to algal toxin consumption at the tap and for those exposed to cyanotoxic blooms during recreational use of lakes, springs and rivers. Without adequate water treatment and coordinated state-wide monitoring efforts, it is anticipated that the likelihood for human exposure to cyanobacteria and their toxins will increase as Florida becomes more dependent upon surface waters to supply a growing population and an expanding urban environment. Coordination and communication between surface water managers and public health officials at the local level will be critical to the overall protection of the environment and public health during toxic cyanobacterial bloom events.
-
A number of countries have developed regulations or guidelines for cyanotoxins and cyanobacteria in drinking water, and in some cases in water used for recreational activity and agriculture. The main focus internationally has been upon microcystin toxins, produced predominantly by Microcystis aeruginosa. This is because microcystins are widely regarded as the most significant potential source of human injury from cyanobacteria on a world-wide scale. ⋯ The major limitations that need to be overcome include: the capacity to deal with multiple toxin congeners, the absence of robust analytical methods for compliance monitoring, and the absence of certified toxin standards to support analyses. However, the current WHO provisional guideline for microcystin-LR, or the other national guideline variants that are based upon it, (e.g., Canadian, Australian) may be appropriate to adopt as a health advisory in the short-term, while regulations are developed. The bathing and recreationa water guidelines developed in other countries could also be translated fo use as recreational water guidelines situation in the US.
-
Pharyngeal muscle tone decreases in sleep and this predisposes some individuals to obstructive sleep apnea. This review summarizes the control of the genioglossus muscle by sleep-state dependent neuromodulators at the hypoglossal motor nucleus, the source of motor output to the genioglossus muscle of the tongue. Knowledge of such mechanisms is relevant to identifying and developing new strategies to augment pharyngeal muscle activity in sleep, potentially as treatments for obstructive sleep apnea.
-
Nebraska agencies and public health organizations collaboratively addressed cyanobacterial issues for the first time after two dogs died within hours of drinking water from a small private lake south of Omaha on May 4, 2004. A necropsy on one of the dogs revealed that the cause of death was due to ingestion of Microcystin toxins. Within two weeks after the dog deaths, state and local officials jointly developed strategies for monitoring cyanobacterial blooms and issuing public health alerts and advisories. ⋯ Four lakes were on health alert for 12 or more weeks. The primary cyanobacterial bloom-forming genera identified in Nebraska lakes were Anabaena, Aphanizomenon, and Microcystis. Preliminary assessments of lake water quality data indicated that lower lake levels from the recent drought and low nitrogen to phosphorus ratios may have contributed, in part, to the increased numbers of cyanobacterial complaints and problems that occurred in 2004.