Brief communication: Extended chronology of the Cordón Caulle volcanic eruption beyond 2011 reveals toxic impacts

Abstract

Abstract. Aside of immediate impacts, the 2011 PuyehueCordón Caulle volcano (PCC) eruption also caused persisting chemical impacts. By 2012, toxicity resulted in overt dental fluorosis in deer, with bone fluoride increasing > 38-fold to 5175 ppm. Sheep, horses and cattle also succumbed to fluorosis. Due to eolian redeposition of tephra, exposure of ruminants continued, bone fluoride reached 10 396 ppm, and by 2014 skeletal fluorosis was found. Nonskeletal fluorosis resulted in reduced wool growth and major losses among periparturient cattle. Peculiarities of digestive processes make ruminants susceptible to fluoride-containing tephra, which averaged 548 ppm from PCC. Moreover, recent volcanic eruptions causing fluorosis could be aggravated by local iodine deficiency, which increases the incidence and harshness of fluorosis, and deficiency of selenium, which, among other things, also results in secondary deficiency of iodine. Notwithstanding, several measures are available to livestock producers to minimize chemical impacts of fluoride.

The eruption of the Laacher See volcano (~13,000 years BP) and possible fluoride poisoning amongst contemporaneous wildlife and human foragers—Outline of a hypothesis and the way to test it

“…Given the petrological measurements of F-contents in undegassed Laacher See ejecta, regions to the north-east of the volcano are of special interest here. While the eruption itself was of a short duration, remobilization of ash due to wind may have circulated the loose ash for some time, as is shown by the observations following the Cordón Caulle volcanic eruption (Flueck, 2016a(Flueck, , 2016b. This example and other observations (Wilson et al, 2011) indicate that the detrimental effects of ash ingestion extend over periods of at least several years following a volcanic eruption.…”

“…Large livestock losses occurred in the area affected by tephra deposition from the Cordón Caulle volcanic eruption (Flueck, 2016b;Stewart et al, 2016). There was also clear evidence for excess Fexposure (elevated bone F-levels) and widespread chronic F-poisoning, especially the occurrence of dental fluorosis, in both livestock and in wild ruminants (Flueck, 2016a;Flueck & Smith-Flueck, 2013). For instance, F-levels in antlers of red deer (Cervus elaphus, a non-native species introduced as hunting game) from the tephra fallout area in Argentina averaged 657 mg/kg (dry wt) in antlers cast in 2012 compared with an average of 63 mg/kg in antlers from 2009, that is, antlers grown prior to the eruption (Flueck & Smith-Flueck, 2013).…”

“…In areas exposed to fallout of volcanic ash, uptake of F-rich tephra particles deposited on the vegetation is considered the dominant exposure pathway for herbivores. Numerous studies of F-toxicosis in grazing animals related to tephra deposition in volcanic areas are available (Araya, Wittwer, Villa, & Ducom, 1990;Armienta et al, 2011;Cronin et al, 2000Cronin et al, , 2003Flueck, 2016a;Flueck & Smith-Flueck, 2013;Georgsson & Petursson, 1972;Roholm, 1937), although these cover only a fraction of possible eruption types and post-eruptive ecological…”

“…Pertinent observations of F-effects on domestic animals and wildlife were more recently made following the eruption in 2011 of the Cordón Caulle volcano located in the Southern Andes of Chile (Flueck, 2014(Flueck, , 2016aStewart et al, 2016). The eruption dispersed tephra over an area of about 350.000 km 2 (extent of the 0.1-mm isopach) east of the volcano, with most of the ash fallout occurring in Argentina.…”