Those of us in the northern hemisphere are at the height of summer, at the biggest summer holiday weekend in the US. Several news articles and studies published this week looked at summertime concerns: heat, skin cancer, outdoor recreation, and air quality. Summertime is a great season for recreation and outdoor play, and a few precautions will help preserve the fun.
Summer heat should always be treated with caution, and an article from the Washington Post features it and other conditions from food poisoning to West Nile virus in The heat and the hazard: 9 facts about summer health. Heat can be especially problematic for the elderly and for infants, and a new study highlights how heat may be more fatal for infants than previously realized: New risk factor for SIDS? Peaks in cot deaths associated with heat waves. Over a 30-year period, when outdoor temperatures exceeded 84°F in Montreal, the incidence of sudden infant death syndrome (SIDS, or crib death) was almost three times as high as when the temperature was 68°F. The study authors point out that “bedroom heating, prone or side sleeping, head covering, overwrapping, swaddling, and bed sharing are all associated with an increased risk of SIDS”, with thermal stress being a common thread.
Exposed skin in summer sunshine brings up the issue of skin cancer. An unexpected factor was found in an analysis of two large ongoing studies with more than two decades of follow up: consuming citrus fruit, especially grapefruit. In Citrus consumption and skin cancer: how real is the link?, the Washington Post describes that furocoumarins in citrus have been known to cause skin to be more sensitive to sunlight. Citrus has recognized benefits to health, and the American Society of Clinical Oncology said that “it’s far too soon for any changes to dietary recommendations about grapefruit and oranges.” However, those who eat or drink citrus five or more times per week may want to take extra precautions in limiting sun exposure.
Two concerns regarding outdoor recreation were in the news this week. Cleveland’s WKYC-TV reports on a new study from Environment and Human Health that “found 96 chemicals in the rubber tire infill used in synthetic turf and rubber tire mulch used as surfacing in toddler playgrounds.” Almost half of those 96 chemicals have had no toxicity testing performed, so any health impacts are unknown. “Of the half that have had toxicity assessments, 20% are probable carcinogens”, and 40% of the chemicals with toxicity testing were found to be irritants for skin, eyes and/or the respiratory system. Some cause asthma symptoms. Public Health Toxicologist David Brown, ScD, added that “it is reasonable to assume that persons playing on synthetic turf fields with rubber tire infill or toddler playgrounds surfaced with rubber tire mulch are being exposed concurrently to multiple chemicals.”
Swimming areas also need scrutiny and vigilance, as described in Centers for Disease Control warns of pool parasite. Diarrhea-causing Crypstoporidum has an outer shell that makes it tolerant to chlorine disinfection. The CDC advises all to “keep the pee, poop, sweat, and germs out of the water!” and not to swallow swimming water.
For many US residents, fireworks displays are the defining moment of the July 4th holiday. Unfortunately, there are some health concerns with fireworks even beyond fire and safety issues. A study from the National Oceanic and Atmospheric Administration (NOAA) released this week describes short-term spikes in particulate matter centered around the evening of July 4th. As summarized in a NOAA article about the study, health effects from fine particles include coughing, wheezing and shortness of breath; asthma attacks; heart attack and stroke; and premature death in people with heart or lung disease. The study authors hope to provide information so that air quality predictions can take fireworks displays into account. EPA recommends that “people who are considered sensitive to particle pollution try to limit their exposure by watching fireworks from upwind—or as far away as possible. People with asthma should follow their asthma action plans and be sure to have their quick relief medicine handy.”
Particle pollution is also affected by weather conditions, as described in Drought conditions make bad air worse, aggravate health problems from the Sacramento Bee. Particles come from exhaust fumes, wood smoke, agricultural fields, road dust and other sources. Droughts make for a double whammy, both because dry conditions increase the risk of fires and otherwise create more particles and because rain is not available to wash particles from the air. The article is written in response to California’s record drought, but similar concerns are likely anywhere that is experiencing drought conditions.
Related to both heat and air quality is air conditioning. Time published an article looking at both the health benefits regarding use of air conditioning—filtering particle pollutants and saving lives during extreme heat waves—and the risks of use—promoting the growth of bacteria and fungi from poorly maintained units and contributing to climate change through electricity use. If air conditioning is used primarily to reduce heat, Dr. Stan Cox, author of Losing Our Cool: Uncomfortable Truths about Our Air-Conditioned World, provides advice on adjusting use without too much discomfort: turn the thermostat up a few degrees and acclimate to the warmer temperatures over a week or two. Keeping air conditioning units maintained and preventing water accumulation from use will reduce the risks of mold and bacteria growth.
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