/oss/taxonomy/term/2040/all en /oss/article/technology-quackery-you-asked/can-dog-rocks-help-stop-my-dog-staining-my-lawn <p>“Dog Rocks” are supposed to solve the problem of grass dying from dog pee. <a href="/oss/article/you-asked/why-does-dog-urine-stain-grass">Urine contains a variety of nitrogen compounds</a>, mostly metabolites of protein in food. These are effective fertilizers, but in the case of urine, they supply too much nitrogen relative to other nutrients and grass suffers the consequences. Drinking water also contains naturally occurring nitrates that can eventually show up in the urine.</p> Thu, 07 Jun 2018 14:07:05 +0000 Joe Schwarcz PhD 7128 at /oss /oss/article/controversial-science-environment-health-news-toxicity/turf-may-be-artificial-issues-are-real <p>There exists a simmering controversy about the safety of playing sports on artificial turf. For those who have engaged in any type of activity on this surface, you would know that they heat up in the sun a whole lot more than natural grass. So much more so that players experience a greater risk of heat exhaustion. They also complain of carpet burns and blisters on the feet. But the bigger concern is potential toxicity.</p> Mon, 13 Jul 2015 11:08:18 +0000 Joe Schwarcz PhD 2275 at /oss /oss/article/general-science-you-asked/why-milk-white-and-not-green-grass <p>Questions about milk are always interesting because, after all, it is our first food. Milk is meant to be the only sustaining food during early life and therefore it must contain all the required nutrients: water, proteins, fats, milk sugar, vitamins and minerals. Chlorophyll, the green colouring agent in plants, is not a required human nutrient and therefore evolution has not resulted in it being incorporated by the mother's body into milk. This is not to say that milk has no coloured substances in it, it does.</p> Wed, 31 Oct 2012 21:58:13 +0000 Joe Schwarcz 1730 at /oss /oss/article/you-asked/why-does-dog-urine-stain-grass <p style="text-align:justify"><a href="http://blogs.mcgill.ca/oss/?attachment_id=3220" rel="attachment wp-att-3220"><img alt="urine burn" height="150" src="http://blogs.mcgill.ca/oss/files/2012/11/dog-150x150.jpg" width="150" /></a>Most homeowners let their dogs use the backyard as their own personal toilet. Often after a winter of such potty practice, when the snow melts, you’ll often find your lawn speckled with unsightly yellow patches.</p> <p style="text-align:justify">First of all, what causes these patches? Dog urine contains a variety of nitrogen compounds. Too much nitrogen will burn the grass and create yellow patches. But appropriate concentrations of nitrogen can actually be beneficial to the lawn, which is why you’ll often see rings of thick dark green grass around the yellow patches. This makes sense, since the main ingredient in lawn fertilizer is nitrogen.</p> <p><a href="http://blogs.mcgill.ca/oss/2012/11/17/why-does-dog-urine-stain-the-grass/">Read more</a></p> Sun, 18 Nov 2012 04:19:26 +0000 Joe Schwarcz PhD 1795 at /oss