Search

Abstract Perfluorohexanoic acid (PFHxA) is a short-chain, six-carbon PFAA and is a primary impurity, degradant, and metabolite associated with the short-chain fluorotelomer-based chemistry used in the United States, Europe and Japan today. With the shift towards short-chain PFAA chemistry, uncertainties remain regarding human health risks associated with current exposure levels. Here, we present a critical review and assessment of data relevant to human health risk assessment to today's short-chain PFAA chemistry. Human biomonitoring surveys indicate that PFHxA is infrequently detected in the environment as well as in human serum and urine; however, human health concerns may persist in locations where PFHxA is detected. In a companion paper (Luz et al., 2019) we comprehensively evaluate the available toxicity data for PFHxA, and derive a chronic human health-based reference dose (RfD) for PFHxA of 0.25 mg/kg-day based on benchmark dose modeling of renal papillary necrosis in chronically exposed female rats. In this paper, we apply this RfD in human health-based screening levels calculations, and derive a drinking water lifetime health advisory of 1400 μg/L and a residential groundwater screening level for children of 4000 μg/L. Compared to environmental concentration data, even sites with more elevated concentrations of PFHxA in the environment are at least an order of magnitude lower than these screening levels. Available PFHxA human serum and urine biomonitoring data, used as a biomarker for general population exposure, demonstrates that the general human population exposures to PFHxA are low. Previous estimates of daily intake rates for infants exposed to PFHxA through breast milk, formula, and baby foods (Lorenzo et al., 2016) combined with the most conservative PFHxA peer-reviewed toxicity value (Luz et al., 2019) demonstrate that the margin of safety for PFHxA is high. Therefore, PFHxA and related fluorotelomer precursors currently appear to present negligible human health risk to the general population and are not likely to drive or substantially contribute to risk at sites contaminated with PFAS mixtures. PFHxA may also represent a suitable marker for the safety of fluorotelomer replacement chemistry used today. Highlights • Human exposure to PFHxA is low and infrequent and PFHxA does not bioaccumulate. • Drinking and ground water screening levels for PFHxA are 1400 and 4000 ppb, respectively. • The highest reported drinking water level of PFHxA is 25,000-fold below the screening level. • The highest reported groundwater level of PFHxA is 33 times lower than the screening level. • For the general population, the margin of safety for PFHxA appears to be high. [ABSTRACT FROM AUTHOR]

In this paper we examine the history, production, and use -- practical and rhetorical -- of maps created by the United States government during World War II as related to the development and execution of aerial bombing policies against Japan. Drawing from a range of maps and primary documents culled from libraries and archives in the United States, we argue that maps provide an important, and hitherto neglected, means through which to trace the exploration and eventual embrace of the incendiary bombing of Japan's cities. In particular, our aim is to show how maps, along with the men who made and used them, played a central role in the planning and prosecution of air raids on urban Japan. We also address the mobilization of American geographers into the war effort, the re-configuration of America's spatial intelligence community during World War II, and the ways in which maps were constructed in the context of total war. [ABSTRACT FROM AUTHOR]

This paper examines the relationship between specialization and happiness in marriage in the U.S. and Japan. Our findings, based on the General Social Surveys in the U.S. and Japan, indicate both similarities and differences in the determinants of marital happiness in the two countries. In the U.S., the findings are mixed. Women’s reported marital happiness in the U.S. is more likely to follow the predictions of the bargaining model where their happiness is determined by their own income. Men’s marital happiness in the U.S. follows the predictions of the specialization model; they are happier if their wives are not working or, alternatively, if they are financially dependent on their wives. In Japan, we find support for the specialization model, particularly in the case of women; they are happier if they are specialized in the household and they have a higher household income. Our research highlights how marital quality is affected by the institutional context and the normative environment. [Copyright &y& Elsevier]

Abstract: Using patent data from the United States, Japan, and Germany, this paper examines both innovation and diffusion of air pollution control equipment. Whereas the United States was an early adopter of stringent sulfur dioxide (SO2) standards, both Japan and Germany introduced stringent nitrogen dioxide (NO X ) standards much earlier than the US. Nonetheless, in both cases, tightened standards in the US led to more domestic patenting, but not more foreign patenting. Overall, the data suggest that inventors respond to environmental regulatory pressure in their own country, but not to foreign environmental regulations. Moreover, any technology transfer that occurs appears to be indirect. Domestic innovation occurs even for technologies that have already experienced significant innovative activity abroad and utilities purchase pollution abatement equipment from domestic firms. However, patent citation data from the US do show that earlier foreign patents are an important building block for NO X pollution control innovations in the US. [Copyright &y& Elsevier]