Madagascar chevrons are V-shaped, coastal dunes of disputed origin. Three distinct chevron complexes were sampled in this chapter: Fenambosy, Ampalaza, and Faux Cap. Chevrons contain abundant carbonate marine microfossils, some partially dolomitized, deposited over along-strike distances of 12 to >40 km. Marine microfossils in the dunes resemble filled-in marine foraminifers, differing from the hollow tests that dominate local beach deposits, and therefore arguing against modern beach deposits being the source of the chevrons' carbonate sands. Chevron dunes sampled in this study are typically not well sorted, with sediment surfaces that slope ≤10 degree. Both observations are inconsistent with an aeolian origin for the deposits. AMS 14 C dating of three carbonate-rich sands yields ages between 13,835 ± 40 and 11,415 ± 35 years before present (year BP), significantly older than modern marine carbonate sediments aged 800 to 418 year BP (i.e., the marine reservoir correction). Assuming that the age range stipulated for carbonate sand represents the maximum plausible age of deposition of the chevrons also argues against a modern aeolian origin. Taken together, characteristics of the chevrons instead support the inference that they are megatsunami deposits possibly related to a Holocene landslide or bolide impact.

Children are the demographic most susceptible to and affected by lead poisoning. Lead contamination in soil has been recorded as being primarily from lead-based paint, historic leaded gasoline emissions, and from lead point-source emitters. The highest risk of elevated blood lead level (BLL) is correlated with living in an area dominated by pre-1950's housing. From 1976 to 1994, midst the phasing out and removal of lead from gasoline, the blood lead levels of children in the United States decreased from 16 µg/dL to 3.2 µg/dL. There is evidence showing the irreversible effects of intellectual impairment still occur at levels of BLL below 10 µg/dL. In Kansas, Barton and Ellis counties residential soils were sampled, and chemical composition was examined with a handheld XRF and an HR ICP-MS. Particle size and pH were recorded for all samples. The presence or lack of of lead sulfate and lead carbonate was identified using XRD. Chemical tests revealed elevated Zn and As with increasing Pb concentrations. There was weak

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