Hexavalent chromium has been identified as an inhalation carcinogen and an air toxin of concern in a number of different locales. The article "Airborne Hexavalent Chromium in Southwestern Ontario" (https://goo.gl/xjTQMS) provided the following data on both indoor and outdoor concentrations (nanograms per cubic meter) for a sample of houses selected from a certain region. ```R airborne <- read.csv("https://W.siue.edu/~jpailde/airborne.csv") head(airborne) # display first 6 rows tail(airborne) # display last 6 rows ``` The data frame is as follows: | House | City | Concentration | Situation | |-------|------|---------------|-----------| | 28 | 29 | 30 | 0.37 | Outdoor | | 1.26 | Outdoor | 0.70 | Outdoor | | 0.76 | Outdoor | 0.99 | Outdoor | | 32 | 33 | 0.36 | Outdoor |
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28 Indoor standard deviation: 0.11 Outdoor mean concentration: 0.68 Outdoor standard deviation: 0.34 ``` ii) To construct boxplots for the concentration for both indoor and outdoor, we can use the following R code: ```r library(ggplot2) indoor_boxplot <- Show more…
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A urine sample of a man suspected of suffering from chromium poisoning was analysed by atomic emission spectroscopy. Chromium standards were prepared at concentrations of 5, 10, 15 and 20 ppm. To 100 cm³ of each standard and to 100 cm³ of the urine sample was added 0.1 cm³ of a 500 ppm yttrium solution. Emission from chromium and yttrium in each solution was then measured with the following results. Solution | Chromium Emission (arbitrary units) | Yttrium Emission (arbitrary units) ---|---|--- 5.0 ppm standard | 13.0 | 6.0 10.0 ppm standard | 28.6 | 6.6 15.0 ppm standard | 31.2 | 4.8 20.0 ppm standard | 46.8 | 5.4 Urine | 31.1 | 5.2 Determine the concentration of chromium in the urine sample in ppm.
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The US Environmental Protection Agency (EPA) places limits on the quantities of toxic substances that may be discharged into the sewer system. Limits have been established for a variety of substances, including hexavalent chromium, which is limited to 0.50 $\mathrm{mg} / \mathrm{L}$ . If an industry is discharging hexavalent chromium as potassium dichromate $\left(\mathrm{K}_{2} \mathrm{Cr}_{2} \mathrm{O}_{7}\right),$ what is the maximum permissible molarity of that substance?
Chromium (VI) can cause severe medical problems when ingested. Which organs in the human body are affected and can show symptoms of chromium poisoning?
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