A Human Health Perspective On Climate Change - The Oceans and ...

8NeurologicalDiseasesand DisordersT he United States has seen an increasing trend in the prevalenceof neurological diseases and deficits. 216 Onset of diseases such asAlzheimer Disease (AD) and Parkinson Disease (PD) is occurringat earlier ages across the population. Environmental factors aresuspected of playing a large role in both the onset and severity ofthese conditions, although there is a gap in our understanding of thisrole, especially in relation to genetics, aging, and other factors. 217While some of these changes in neurological health likely are due tothe aging of a large portion of the population, learning disabilitiesthat affect children also are on the rise, and there are indicatorsthat environmental factors may be involved including changes inclimate that may exacerbate factors affecting the rates and severityof neurological conditions. 218,219 Neurological conditions generallycarry high costs in terms of quality of life for both the sufferer andthe caregiver and increased healthcare stresses on the economyand the workforce. The combination of these factors could affect asizable portion of the U.S. population, and have significant impactson productivity.Factors affected by climate with particular implications for neurologicalfunctioning include malnutrition; 220 exposure to hazardouschemicals, biotoxins, and metals in air, food, and water; 221 andchanges in pest management. 222 Understanding the role of climate inthe incidence and progression of neurological conditions and how toprevent them is a critical need for public health and health care in theUnited States. Studies such as the National Children’s Study 223 are anexcellent opportunity to improve our understanding in this area.Impacts on RiskNumerous recent reports have described observed and anticipateddetrimental effects of climate change on ocean health, resultingin increased risks to neurological health from ingestion of orRESEARCH HIGHLIGHTHarmful algal blooms (HABs) areincreasing worldwide and globalclimate change is thought to play asignificant role. Many HAB-relatedbiotoxins cause significant neurotoxiceffects in both animals and humansincluding permanent neurologicalimpairment. The algae Pseudonitzschiaspp. produce domoic acid,a potent neurotoxin that causesamnesiac shellfish poisoning in people. Blooms of this algae have beenincreasing off the California coast resulting in significant illness anddeath in marine animals. A decade of monitoring of health of Californiasea lions, a sentinel species for human health effects, indicates changesin the neurologic symptomatology and epidemiology of domoicacid toxicosis. Three separate clinical syndromes are now present inexposed animals: acute domoic acid toxicosis with seizure, permanenthippocampal atrophy, and death; a second novel neurological syndromecharacterized by epilepsy associated with the chronic consequences ofsub-lethal exposure to domoic acid; and a third syndrome associatedwith in utero exposures resulting in premature parturition, neonataldeath, and significant neurotoxicity in the developing fetus resulting inseizure activity as the animal grows, as well as long-lasting impacts onmemory and learning. 1 These observations indicate significant potentialimplications for human health effects, although their exact nature is notknown and needs further study.216 Steenland, K, et al., Alzheimer Dis Assoc Disord, 2009. 23(2): p. 165-70.217 Bronstein, J, et al., Environmental Health Perspectives, 2009. 117(1): p. 117-121, Hendrie, HC, et al., Canadian Journalof Psychiatry-Revue Canadienne De Psychiatrie, 2004. 49(2): p. 92-99, Mayeux, R, Annals of Neurology, 2004. 55(2):p. 156-158.218 Bronstein, J, et al., Environmental Health Perspectives, 2009. 117(1): p. 117-121, Mayeux, R, Annals of Neurology,2004. 55(2): p. 156-158, Jones, L, et al., Lancet, 2009. 374(9690): p. 654-61.219 Altevogt, BM, et al., Pediatrics, 2008. 121(6): p. 1225-1229.220 Kar, BR, et al., Behav Brain Funct, 2008. 4: p. 31.221 Kozma, C, Am J Med Genet A, 2005. 132(4): p. 441-4, Papanikolaou, NC, et al., Med Sci Monit, 2005. 11(10): p.RA329-36.222 Handal, AJ, et al., Epidemiology, 2007. 18(3): p. 312-20.223 Landrigan, PJ, et al., Pediatrics, 2006. 118(5): p. 2173-86.1 Goldstein, T, et al., Proceedings of the Royal Society B-Biological Sciences, 2008. 275(1632): p. 267-276.Ramsdell, JS and TS Zabka, Marine drugs, 2008. 6(2): p. 262-90.www.niehs.nih.gov/climatereport 41