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- Mass<\/strong> – The base unit of measurement is the gram. This is about the weight of a dime. If we had 1000 dimes, it would weigh 1 kg. Similarly, if\u00a0we have 1 gram of mercury, we would have 1000 mg, or 1,000,000 \u0173g of mercury.\n
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- There are 1,000 milligrams in one gram and about 28 grams in one (English) ounce.<\/li>\n<\/ul>\n<\/li>\n
- Volume –<\/strong> The base unit of measurement of volume is the liter.\u00a0If we had one litre of water, we would have 1000 mL. \u00a0Likewise, if we had 1 mL of water, we would have .001 L of water.<\/li>\n
- Concentration –<\/strong> A concentration is the relationship between the amount of a substance you have, and the space you’re fitting it into. For materials dissolved in water, the concentration is usually given as mg\/L, but many other systems exist.\n
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- Milligrams\/liter (mg\/l) <\/strong>\u00a0is the most common way to describe\u00a0a concentration in water and is roughly equivalent to parts per million.<\/li>\n
- Example: \u00a0 Health Canada guidelines for water contaminants, Maximum Allowable Concentration for mercury is 0.001 mg\/L. This means that for every liter of water, there should be no more than 0.001 mg, or 0.000001 grams of mercury. \u00a0In the US, the EPA standard\u00a0for arsenic in drinking water<\/a> is 0.01 mg\/L, or\u00a0\u00a010 parts per billion (ppb).<\/li>\n<\/ul>\n<\/li>\n
- PPM & PPB\u00a0<\/strong>\u00a0– It’s also common to express\u00a0\u00a0concentration in parts-per-million (ppm) or parts-per-billion (ppb). \u00a0A 1 ppm concentration of sugar in your coffee would mean that there is one sugar molecule for every million coffee “molecules.”\n
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- One PPM is like one second in a month; one PPB is like one second in 32 years.<\/li>\n
- One PPM is like\u00a0one teaspoon of water in a 21 foot diameter, 4 foot deep swimming pool; \u00a0one PPB is like one one-thousandth of that teaspoon.<\/li>\n<\/ul>\n<\/li>\n
- More examples:<\/strong>\n
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- The lowest concentration at which most people can taste chlorine in their water is 0.156 ppm.<\/li>\n
- Most people can just barely smell a skunk when the concentration of the animal’s scent is at 1 ppm in the air.<\/li>\n<\/ul>\n<\/li>\n<\/ul>\n
Radiation<\/strong>
\nIt\u2019s often said that radiation is natural, and that we are exposed to increased radiation just by\u00a0flying in airplanes and sitting in the dentists chair. \u00a0To put these sorts of statements into perspective, the Guardian newspaper created this table<\/a> explaining effects of various levels of radiation damage, expressed in millisieverts<\/a>.<\/p>\n\n
\n \n\n <\/colgroup>\n \n Event<\/strong><\/td>\n Radiation reading, millisievert (mSv)<\/strong><\/td>\n<\/tr>\n \n Single dose, fatal within weeks<\/td>\n 10,000<\/td>\n<\/tr>\n \n Typical dosage recorded in those Chernobyl workers who died within a month<\/td>\n 6,000<\/td>\n<\/tr>\n \n Single dose which would kill half of those exposed to it within a month<\/td>\n 5,000<\/td>\n<\/tr>\n \n Single dose which would cause radiation sickness, including nausea, lower white blood cell count. Not fatal<\/td>\n 1,000<\/td>\n<\/tr>\n \n Accumulated dosage estimated to cause a fatal cancer many years later in 5% of people<\/td>\n 1,000<\/td>\n<\/tr>\n \n Max radiation levels recorded at Fukushima plant (Oct. 2015), per hour<\/td>\n 400<\/td>\n<\/tr>\n \n Exposure of Chernobyl residents who were relocated after the blast in 1986<\/td>\n 350<\/td>\n<\/tr>\n \n Recommended limit for radiation workers every five years<\/td>\n 100<\/td>\n<\/tr>\n \n Lowest annual dose at which any increase in cancer is clearly evident<\/td>\n 100<\/td>\n<\/tr>\n \n CT scan: heart<\/td>\n 16<\/td>\n<\/tr>\n \n CT scan: abdomen & pelvis<\/td>\n 15<\/td>\n<\/tr>\n \n Dose in full-body CT scan<\/td>\n 10<\/td>\n<\/tr>\n \n Airline crew flying New York to Tokyo polar route, annual exposure<\/td>\n 9<\/td>\n<\/tr>\n \n Natural radiation we\u2019re all exposed to, per year<\/td>\n 2<\/td>\n<\/tr>\n \n CT scan: head<\/td>\n 2<\/td>\n<\/tr>\n \n Spine x-ray<\/td>\n 1.5<\/td>\n<\/tr>\n \n Radiation per hour detected at Fukushimia site, 12 March<\/td>\n 1.015<\/td>\n<\/tr>\n \n Mammogram breast x-ray<\/td>\n 0.4<\/td>\n<\/tr>\n \n Chest x-ray<\/td>\n 0.1<\/td>\n<\/tr>\n \n Dental x-ray<\/td>\n 0.005<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n Types of radiation<\/strong> — It’s also important to understand the types of radiation.\u00a0 Alpha particles<\/a> (for example, from plutonium 239) may not be energetic enough to penetrate a sheet of paper, but they are deadly if ingested.\u00a0 Beta particles<\/a> are moderately energetic and may also cause significant tissue damage.\u00a0 Gamma radiation<\/a> is highly energetic and also dangerous.<\/p>\n
<\/p>\n
![\"\"](\"https:\/\/revolutionsincommunication.com\/journalism\/wp-content\/uploads\/2021\/02\/Radiation.Dose_.Chart_-255x300.jpg\")
<\/a><\/p>\n","protected":false},"excerpt":{"rendered":"Scientific measurements almost exclusively use the metric system. Each variable – mass, length, time, has a base unit in which everything is measured. They are then given prefixes to make the numbers easier to work with in calculations or conversation. … Continue reading
- Example: \u00a0 Health Canada guidelines for water contaminants, Maximum Allowable Concentration for mercury is 0.001 mg\/L. This means that for every liter of water, there should be no more than 0.001 mg, or 0.000001 grams of mercury. \u00a0In the US, the EPA standard\u00a0for arsenic in drinking water<\/a> is 0.01 mg\/L, or\u00a0\u00a010 parts per billion (ppb).<\/li>\n<\/ul>\n<\/li>\n
- Concentration –<\/strong> A concentration is the relationship between the amount of a substance you have, and the space you’re fitting it into. For materials dissolved in water, the concentration is usually given as mg\/L, but many other systems exist.\n