How Humans Caused Our Own Allergies - Cheddar Explains

Durham North Carolina 2019 a blanket of pollen covered the city it looked like something out of a horror movie said photographer jeremy gil christ residents were sneezing and coughing and it got so bad some had to be put on antibiotics your car was suddenly yellow the sidewalk was yellow the roof of your house was yellow said Kevin Lilly assistant director of the city's Landscape Services the area had around a thousand eight hundred grains of pollen per cubic meter of air how could this even happen after all Nature has been functioning perfectly for all this time and we never hear about historical allergies in fact we didn't hear about bad allergies before the 1970s why is that the pollen pocalypse has been building for decades to really learn how this happened we have to go back to the Netherlands 1910 something was killing the elm trees crazy patterns were showing up on trunks of trees and whole trees would wilt and die in as little as a month and it was contagious whole forests were turning brown and dying and there really wasn't any way to stop it the cause was discovered by Dutch phyto pathologist B Schwartz in 1922 she isolated the fungus behind the tree does it was carried by bark beetles which would bury beneath the bark of elm trees and eat the dry wood shedding fungal spores by the million after decimating European trees the bark beetles hopped on board a shipment of logs from Britain to the US which was a big problem because in the Edwardian era elm trees would the tree of choice in America cities and towns were lined with stately elm trees that were loved both for their straight trunks and because they're hermaphrodites wait what that's right hermaphrodites to reproduce some trees have flowers that give off pollen and some trees sprout flowers to be pollinated the trees that give off pollen are male you can tell they're male because they have a salmon and the trees that sprout pollinated flowers and seed pods are female they have a stigma elm trees have both pollinated flowers and give off pollen trees that have separate genders are called dioecious like cedar you and ash trees that are hermaphrodites are called Manutius like elm birch oak and pine trees that have both male and female parts in the same flower are called perfect like apple and hazelnut trees because elm trees are hermaphrodites or Manisha's they release pollen but they also catch it it was part of the reason they were planted so widely in the 1900s they didn't drop a lot of litter and they didn't release a lot of pollen but the lack of diversity was a recipe for disaster when Dutch elm disease hit it decimated the American elm population and by 1989 an estimated 75% of North America's 77 million elm trees were dead that's around 58 million trees many American streets were bare there certainly wasn't any pollen so how did we get to the pollen pocalypse today you can blame it on one short sentence in the 1949 USDA book called yearbook of Agriculture when used for Street plantings only male trees should be selected to avoid nuisance from the seed so that's what city planners and landscapers did they planted male trees all over the US the USDA figured that pollen would be blown away by wind or washed away by rain making pollen an easier civic duty to manage than seed pods or overripe fruit that would actually have to be cleaned up by people but city planners and landscapers didn't stop there landscapers also used cloned male trees all over the US and cloned male plants dominated nurseries it was easier to clone plants than wait for male and female plants to pollinate so male clones became the norm after the USDA 1949 guidelines were released the USDA produced and released into the market almost 100 new red maple and hybrid maple clones and every single one of them was male you might be thinking Ali there's no way they were actually cloning plants in the 1950s but cloning in terms of plants actually means something different it's a way of propagating plants where you take a cutting of the original plant and it grows into its own plant it also allows for some non natural selection the wholesale growers learned how to select a male Scion wood from trees that were malicious and we started to see trees never-before-seen in nature such as seedless Cyprus and podlasie locust trees these new hyper male plants didn't drop any seeds or fruit and for a while people thought they had beaten nature but Nature had other plans after the post Dutch elm disease replanting it took a number of years for the new young trees to mature enough to start blooming eventually they did bloom and with them came the epidemic of Allergy and Asthma many of those original trees are still alive and well and getting even bigger and the bigger they get the more pollen they shed male trees and plants all over the nation began shedding tons and tons of pollen there were no female trees to catch the pollen so it swept over towns and cities in yellow clouds scientists had discovered in 1873 that pollen grains were a causative agent behind allergies but they didn't discover until 1967 that the cause of seasonal allergies was pollen aggravating our own antibodies antibodies released by your immune system attached to the allergens and then trigger the release of the inflammatory chemical histamine which is what causes your eyes to itch and your nose to run but nobody had made a connection between our worsening allergies and the overabundance of pollen producing trees Tom Agron was working as a prison landscaper in San Luis Obispo California in the 1990s his wife Yvonne was suffering from some bad allergies and he wasn't convinced he was reading a book about how allergies which hit women hardest are psychosomatic or our brains invent them and he agreed but when his workers underneath a certain kind of tree or sniffling and sneezing more than the others Agron realized that the plants producing the most allergy triggering pollen were male and that most municipal plantings were using just male plants to mitigate the droppings it was a breakthrough he was the first person to link exacerbated allergies with urban planting policy Agron threw himself into this discovery he got a master's in horticulture and has written three books on the subject he developed the oghren plant allergy scale called opals to rate trees from one to ten on their allergy potential it's intended to guide cities to plant less allergenic trees Agron calls it botanical sexism he argues that if cities had planted the opposite all female instead of all male it would have been just as sterile and tidy without any pollen because female trees don't make fruits or seeds if there are no males around a large tree will scatter its pollen within 20 to 30 feet of its roots so female trees would simply have to be planted outside of that range to avoid most pollination another argument against female trees is that some smell really bad like the female gingko tree when the female gingko is in heat people say it smells like rotting fish or vomit but Agron likes to argue if the city only planted female ginkgo it'd be less likely they'd be fertilized there'd be no post quit Oh odor and no pollen ogron's biology stands up to academic scrutiny in the field of horticulture and urban forestry but many experts dislike calling its botanical sexism they think ascribing a very human problem to the botanical world is trivializing unfortunately ogron's work is an uphill battle not only our state's slow on the uptake of opals but our environment is making the problem even worse according to a recent study the increase in extreme temperatures that we've seen in the last few years thanks to global warming is contributing to more potent allergy seasons plus high levels of carbon dioxide caused trees to produce pollen add up to four times in their natural rate summers come earlier and last longer and certain species such as Cypress and juniper have allegedly begun blooming again in the fall so thanks to global warming we have earlier and longer budding seasons and increased pollen production and the pollen problem is clear across the country 70% of the trees are male dioecious trees chosen to be hardy in winter and withstand smog but very pollen releasing it's a problem that doesn't have an immediate solution because no one is going to cut down trees just because they cause us allergies the only thing that we can do is replant with trees low on the oppo scale for now we have to live with the millions and millions of male trees that we planted so when you're cursing nature this spring because of your sniffles we suggest redirecting because we did this to ourselves what do you think about seasonal allergies let us know in the comments make sure you like this video click Subscribe and don't forget to ring the bell for post notifications we'll see you next time [Music]

Channel: Cheddar

Views: 444,574

Rating: 4.866889 out of 5

Keywords: Cheddar, cheddar explains, explainer, allergies, allergic, what causes allergies, allergy, allergies explained, allergic reaction, weird allergies, nasal allergies, pollen allergies, spring allergies, strange allergies, odd allergies, springtime, sneezing, pollen, trees, pollenpocalypse, spring, seasonal allergies, male trees, pollution

Id: Fh758qVQPqg

Length: 11min 38sec (698 seconds)

Published: Tue Apr 21 2020

Reddit Comments

[u/Quartnsession]

All those homeless tape worms not suppressing our immune systems anymore.