Expert Commentary

Cold weather problems and risks: Research roundup

2013 review of scholarly literature and government reports on winter weather and human activities, including on how to prevent or manage some of the season’s worst threats.

Snowstorm (iStock)
(iStock)

The approach of the first winter storm usually raises a number of issues and problems that are of keen interest to scientists and social scientists. While snowfall accumulation often is the focus of breaking-news coverage, there are many other data-driven ways to look at storms and the challenges that cold weather present.

Of course, snow, rain, sleet and ice can make travel treacherous, and populations with mobility challenges such as the elderly and disabled often find themselves confined to their homes. Other adverse effects of winter weather include power outages, fires, business closures, building collapses and shutdowns of public transportation as well as injuries related to snow shoveling, carbon-monoxide poisoning and frostbite. Many local stories concentrate on individual incidents, but news coverage can be better informed by wider research on general patterns and data.

The U.S. Centers for Disease Control and Prevention has materials that provide a broad perspective on winter-emergency preparedness and response, including how to prevent or manage some of winter’s worst threats. The National Weather Service offers customizable data on current and predicted snowfall in different areas of the United States.

In an age of human-induced climate change, there are inevitably conversations about attributing weather events to wider phenomena, and there is an emerging area of research examining how changes in Earth’s systems may impact the winter season, even possibly making it colder in some regions. For insights informed by science — with applications for media members — see the 2014 article published in Nature Climate Change, “Impacts: Heated Debate on Cold Weather.” For anyone looking to do a feature on the topic, the National Research Council published a useful 2014 conference report “Linkages Between Arctic Warming and Mid-Latitude Weather Patterns.”

The following is a list of useful studies relating to winter’s impact:
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Did Abnormal Weather Affect U.S. Employment Growth in Early 2015?”
Report from the Federal Reserve Bank of Boston, June 2015.

Abstract: “This research note investigates the relationship between the abnormally severe winter experienced in many parts of the United States and the pattern of monthly employment growth during the first four months of 2015. The results suggest that weather reduced employment growth substantially in March and raised it in April. But the overall weather effect averages out to near zero when the four months are considered as a whole, so weather cannot explain the general slowdown in U.S. employment growth experienced since 2014 ended. More generally, the results show that aligning weather data to be consistent with the point-in-time nature of employment surveys is critical for this type of study. In fact, giving more weight to weather occurring just before survey weeks may deliver better estimates of abnormal weather’s effects on employment.”

 

How Does Variation in Winter Weather Affect Deer-Vehicle Collision Rates?
Wildlife Biology, 2015, Vol. 21, pp. 80-87. doi: dx.doi.org/10.2981/wlb.00043.

Abstract: “Understanding how deer move in relationship to roads is critical, because deer are in vehicle collisions, and collisions cause vehicle damage, as well as human injuries and fatalities. In temperate climates, mule deer Odocoileus hemionus have distinct movement patterns that affect their spatial distribution in relationship to roads. In this paper, we analyzed deer movements during two consecutive winter seasons with vastly different conditions to determine how deer-vehicle collision rates responded … Our data suggest a mechanism by which variation in winter conditions can contribute to differences in deer-vehicle collision rates between years. These findings have significant management implications for deer-vehicle collision mitigation.”

 

“Snow Shovel-Related Injuries in U.S., 1990 to 2006”
American Journal of Emergency Medicine, January 2011, Vol. 29, No. 1, pp. 11-17.

Findings: “Musculoskeletal exertion was involved in 54% of the cases; slips and falls represented 20%; and a snow shovel striking a person caused 15% of incidents. Sprains, strains, contusions, and abrasions — ‘soft-tissue injuries’ — were diagnosed in 55% of the admissions; lower back injuries constituted 34.3%. Cardiac-related incidents comprised 6.7% of cases; they caused half of all hospitalizations and all 1,647 deaths. Two-thirds of the cases involved males, with the median age being 39; persons over age 55 comprised 21.8%; and children accounted for 15.3% of cases. Children were almost 15 times more likely of being injured by being struck by a snow shovel than adults were. For the 125,900 cases in which the location was documented, 95.6% happened around the home.”

 

“Severe Weather Warnings Predict Fracture Epidemics”
Injury, July 2011, Vol. 42, No. 7, 687-690. doi: 10.1016/j.injury.2010.12.012.

Abstract: “Winter epidemics of fractures have been described that greatly exceed normal seasonal variations and overwhelm resources. We investigated the relationship between severe weather warnings, the frequency of fractures, and fracture related workload. There was a significant increase in fractures with cold and inclement weather, mostly low-energy fractures treated with day-case surgery or in fracture clinics. The number of patients treated as inpatients for fractures did not increase. Hip fractures were not associated with weather. Severe weather warnings for icy roads were predictive of fracture epidemics (p < 0.01) with an associated 40% (95% confidence limits 20–52%) increase in fractures. Meteorological Office issued severe weather warnings can provide a trigger to plan for an increased workload of low-energy fractures, with opportunities for anticipatory public health measures.”

 

“Changes in Ice Storm Impacts over Time: 1886–2000”
Weather, Climate and Society, January 2011, Vol. 2, No. 1, 23-35pp. doi: 10.1175/2009WCAS1013.1.

Abstract: “Ice storms have a variety of negative effects on society. Through an analysis of newspaper accounts of nine exceptional ice storms, the most widespread and longest lasting impact is the loss of electrical power. Power outages also cause secondary effects, such as carbon monoxide poisoning and fire, and they can force people to leave their homes because of a lack of heat. Other impacts of ice storms are transportation disruptions, school and business closings, and economic losses to agriculture and some business sectors. However, some businesses, such as those associated with the hospitality sector, actually benefit from ice storms. Modern power outages have a longer duration than those associated with earlier storms. Rural areas are most likely to suffer from long power outages because utilities prioritize areas with greater numbers of customers and because fallen trees may limit accessibility. Several suggestions for reducing electrical disruption, such as aggressive tree-trimming programs and burial of lines, are analyzed. While these may help, less reliance on electricity for lighting and heating systems could also provide a benefit.”

 

“Power System Reliability Assessment Considering the Effect of Freezing Weather”
Power and Energy Engineering Conference (APPEEC), 2010 Asia-Pacific, 28-31 March 2010.

Summary: The impact of weather on power-system reliability is increasing. This paper focuses on the relevance between freezing weather and system reliability.

 

“A Review of Disaster-Related Carbon Monoxide Poisoning: Surveillance, Epidemiology, and Opportunities for Prevention”
American Journal of Public Health: October 2012, Vol. 102, No. 10, pp. 1957-1963. doi: 10.2105/AJPH.2012.300674

“We conducted a systematic literature review to better understand aspects of disaster-related carbon monoxide (CO) poisoning surveillance and determine potentially effective prevention strategies…. This review included information from 28 journal articles on disaster-related CO poisoning cases occurring between 1991 and 2009 in the United States…. We identified 362 incidents and 1888 disaster-related CO poisoning cases, including 75 fatalities. Fatalities occurred primarily among persons who were aged 18 years or older (88%) and male (79%). Hispanics and Asians accounted for 20% and 14% of fatal cases and 21% and 7% of nonfatal cases, respectively. Generators were the primary exposure source for 83% of fatal and 54% of nonfatal cases; 67% of these fatal cases were caused by indoor generator placement. Charcoal grills were a major source of exposure during winter storms. Most fatalities (94%) occurred at home. Nearly 89% of fatal and 53% of nonfatal cases occurred within 3 days of disaster onset…. Public health prevention efforts could benefit from emphasizing predisaster risk communication and tailoring interventions for racial, ethnic, and linguistic minorities. These findings highlight the need for surveillance and CO-related information as components of disaster preparedness, response, and prevention.”

 

“Recreational Snow-Sports Injury Risk Factors and Countermeasures: A Meta-Analysis Review and Haddon Matrix Evaluation”
Sports Medicine, August 2015, Vol. 45, pp. 1175-1190. doi: 10.​1007/​s40279-015-0334-7.

Summary: The researchers reviewed 98 articles on snow sports and used data from 55 studies to identify risk factors for injuries and determine the effectiveness of injury-prevention measures. They found that “more experienced skiers and snowboarders are more likely to sustain an injury as a result of jumps, while beginners sustain injuries primarily as a result of falls.” The study suggests that interventions focus on four key factors: beginner skiers, beginner snowboarders, skiers and snowboarders who rent snow equipment and visibility issues caused by weather. The authors determined that effective countermeasures include helmets for skiers and snowboarders and wrist guards for snowboarders.

 

“Pedestrian Behavior and Safety on a Two-Stage Crossing with a Center Refuge Island and the Effect of Winter Weather on Pedestrian Compliance Rate”
Accident Analysis and Prevention, July 2010, Vol. 42, No. 2, pp. 1156-1163.

Abstract: “The purpose of this study was to determine whether pedestrian behavior becomes more risky in inclement weather through the investigation of street crossing behavior and compliance under different weather and road surface conditions at a busy two-stage crossing. Road crossing behavior was filmed at one eight-lane divided road strip at a downtown site in Toronto metropolitan area. The intersection was filmed unobtrusively from a rooftop by one camera set to record both oncoming near-side traffic and pedestrian movements. Pedestrian behavior and compliance rate were scored for a number of determinants of safe road crossing actions. Overall, the results show that road crossing behavior in inclement weather conditions was less safe than in fine weather. The designs of signal timing and configuration of the center refuge island also adversely influenced pedestrian behavior at this crossing, and adverse weather conditions further exacerbated the noncompliance rate. This paper presents new information on compliance rate at a two-stage crossing that emphasizes the need to consider the influence of traffic signal design and weather conditions on pedestrians’ behavior.”

 

“Traffic Flow Characteristics of Urban Expressway in the Period of Ice and Snow of Cold Areas”
Traffic and Transportation Studies 2010. Seventh International Conference on Traffic and Transportation Studies (ICTTS) 2010. doi: 10.1061/41123(383)41.

Abstract: “Urban expressway is a rapid arterial that connects main areas of the city, and meets the great-amount, long-distance, and high-speed demand of urban traffic. The friction coefficient of roads covered with snow and ice is reduced, and the traffic operation risk is increased in regions with high latitudes, whose winter is long and cold, and those conditions led to the reduction of road capacity and the increase of traffic delays. Using the video detection device, one of the traffic flow information collecting devices, a large number of data in the period of ice and snow of cold area are collected, which is the research base of this paper. The macro and micro traffic flow characteristic of urban expressway under conditions of the snow and ice environment are analyzed, such as the instant traffic flow, the distribution of headway time, and the properties of the speed distribution. The relation models of speed-volume are built. At the same time, the traffic flow characteristic of the urban expressway in the period of ice and snow of cold areas are compared with that of non-snow periods. The outcomes studied above are the foundation for analyzing traffic operation and capacity of urban expressway in the period of ice and snow.”

 

“The Effects of Weather on Walking Rates in Nine Cities”
Environment and Behavior, November 2012, Vol. 44, No. 6, pp. 821-840. doi: 10.1177/0013916511409033.

Abstract: “This study examined whether locally felt weather had a measurable effect on the amount of walking occurring in a given locale, by examining the observed walking rate in relation to air temperature, sunlight, and precipitation. Web-based cameras in nine cities were used to collect 6,255 observations over 7 months. Walking volumes and levels of precipitation and sunlight were captured by visual inspection; air temperature was obtained from local meteorological stations. A quasi-Poisson regression model to test the relationship between counts of pedestrians and weather conditions revealed that all three weather variables had significant associations with fluctuations in volumes of pedestrians, when controlling for city and elapsed time. A 5°C increase in temperature was associated with a 14% increase in pedestrians. A shift from snow to dry conditions was associated with an increase of 23%, and a 5% increase in sunlit area was associated with a 2% increase.”

 

“Wheelchair Ramp Navigation in Snow and Ice-Grit Conditions”
Archives of Physical Medicine and Rehabilitation, October 2010, Vol. 91, No. 10, pp. 1516–1523. doi: 10.1016/j.apmr.2010.07.215.

Findings: “Even with sufficient grit, the more active subjects frequently had wheel slip issues during ascent at the 1:10 and 1:12 slopes (ie, stronger propulsive motion surpasses wheel-ice-grit friction). These subjects typically used a 2-railing approach to reinitiate motion and then reverted to standard propulsion. Two-railing propulsion could be recommended as the primary strategy for ice conditions because friction issues are resolved (ie, no propulsive force on wheel rims), control of wheelchair trajectory is improved, and a stronger propulsive force can be generated. Snow conditions produced a very different situation across ramp grades. The 1:10 grade was insurmountable for many subjects without assistance. As mentioned previously, the main issue was the front wheels becoming embedded in the snow. Without the ability to lean back, clear the front wheels from the snow, and propel the wheelchair forward, external assistance to clear the wheels from the rut was the only way to reinitiate forward progression. Raising the front wheels with a small wheelie maneuver becomes more difficult as the slope increases.”

 

“Accident Prediction Models for Quantifying Safety Benefit of Winter Road Maintenance”
Transportation Research Board 89th Annual Meeting, 2010, 23pp.

Abstract: “This research presents a modeling approach to investigate the association of the accident frequency during a snow-storm event with road surface conditions, visibility and other influencing factors controlling for traffic exposure. This methodology can be applied to the evaluation of different maintenance strategies using safety as a performance measure. As part of this approach, this research introduces a road surface condition index (RSI), similar to the commonly used friction measure, and uses this index as a representation of different road surface conditions. After the combination of different data sources, three event-based models including the Negative Binomial model (NB), the generalized NB model (GNB) and the zero inflated NB model (ZINB) are developed and compared for their capability to explain differences in accident frequency between individual snow storms. It was found that the GNB model best fits the data, and is most capable of capturing heterogeneity other than excess zeros. Among the main results, it was found that the RSI was statistically significant influencing the accident occurrence. According to our proposed index, our results suggest that a 10% improvement in road surface condition would lead to nearly an 11% reduction in the expected number of accidents. This research is the first showing the empirical relationship between safety and road surface conditions at a disaggregate level (event-based), making it feasible to quantify the safety benefits of alternative maintenance goals and methods.”

 

“Snow-Induced Building Failures”
Journal of Performance of Constructed Facilities, Vol. 26, No. 4, pp. 377-388. doi: 10.1061/(ASCE)CF.1943-5509.0000222.

Abstract: “This study examines 1,029 snow-induced building failure incidents in the United States between 1989 and 2009 and 91 international incidents between 1979 and 2009. Incidents were identified through newspaper archives, including 1,345 articles from 883 unique sources. Most U.S. incidents occurred in New York, New Hampshire, and Massachusetts. Findings show that 37% of all buildings experiencing snow-induced failure incidents in the United States were of metal/steel construction and another 37% were of timber, while 53% of international incidents were metal/steel and 17% were concrete. Warehouses, factories, and commercial buildings were the most common buildings affected. Failures were attributed to the amount of snow, rain-on-snow mixes, and building problems. Monetary impacts included building damages ranging between $1,000 and $200 million and business interruption associated with an average building closure of four months. Nineteen fatalities and 146 injuries were reported for the United States, while 293 fatalities and 586 injuries were reported internationally. These findings describe building failure trends, which may be significant, considering potential impacts of accelerating global climate change on the patterns of snowfall frequency and density.”

 

“Frostbite”
Baylor University Medical Center Proceedings, July 2010, Vol. 23, No. 3, pp. 261-262.

Findings: “Potential patients are policemen, farmers, mail carriers, homeless people, chronic alcoholics, psychiatric patients, fishermen, victims of automobile breakdowns, and returning recreational skiers. Our bodies are thought to conserve body heat by first constricting vessels to organs not essential to life. The areas first affected are those furthest from the heart, “ears and nose, fingers and toes.” Frostbite occurs when unprotected skin is exposed to temperatures of 21°F; the insult is made worse by cold winds. The tissues freeze and ice crystals form in the cells. Most cells can survive freezing and subsequent thawing, but the small blood vessels are usually so damaged that clots obstruct the circulation. This risk is increased in those with diabetes or Raynaud’s disease, as well as heavy alcohol consumers. Those exposed to the risk of frostbite need to wear layers of insulated nonconstrictive clothing and protect themselves from moisture. Our feet are particularly susceptible; gravity drains sweat into one’s socks, increasing the risk of frostbite. Swedish research has shown that wet socks combined with motion may reduce insulation protection by 45%.”

 

“Safety Effects of Winter Weather: The State of Knowledge and Remaining Challenges”
Transport Reviews: A Transnational Transdisciplinary Journal, Vol. 30, No. 6, pp. 677-699. doi: 10.1080/01441640903414470.

Abstract: “In recent years, there has been growing recognition of the effects of weather on the surface transportation system. Although considerable work has been done in quantifying the effects of weather on the highway system, there is still much that remains unknown about the relationship between weather and highway system performance. This paper synthesizes the findings from some of the major efforts in this area. The review of existing studies found consistent patterns that adverse weather reduces traffic speed and increases crash frequencies, while fatal crashes are decreased. A table is then presented which estimates the change in crash frequency and vehicle travel speed resulting from various winter weather conditions, based on a synthesis of earlier work. To estimate the safety and speed adjustment factors of compacted snow, a severity index is also developed. Recognizing the lack of comparability between the results of the studies, the paper concludes with a detailed discussion of avenues for future research which could help to address some of the gaps which currently exist. These challenges include, but are not limited to: quantification of the dynamic layer, development of the relationship between pavement friction and the composition of the dynamic layer, evaluation of the effects of pavement friction on vehicle speed, and evaluation of safety effects of weather conditions above the pavement.”

 

“Seasonal Affective Disorder”
American Family Physician, December 2012, Vol. 86, No. 11, 1037-41.

Abstract: “Seasonal affective disorder is a combination of biologic and mood disturbances with a seasonal pattern, typically occurring in the autumn and winter with remission in the spring or summer. In a given year, about 5 percent of the U.S. population experiences seasonal affective disorder, with symptoms present for about 40 percent of the year. Although the condition is seasonally limited, patients may have significant impairment from the associated depressive symptoms. Treatment can improve these symptoms and also may be used as prophylaxis before the subsequent autumn and winter seasons. Light therapy is generally well tolerated, with most patients experiencing clinical improvement within one to two weeks after the start of treatment. To avoid relapse, light therapy should continue through the end of the winter season until spontaneous remission of symptoms in the spring or summer. Pharmacotherapy with antidepressants and cognitive behavior therapy are also appropriate treatment options and have been shown to be as effective as light therapy. Because of the comparable effectiveness of treatment options, first-line management should be guided by patient preference.”

 

“This is Your Portfolio on Winter: Seasonal Affective Disorder and Risk Aversion in Financial Decision Making”Social Psychological and Personality Science, March 2012, Vol. 3, No. 2, pp. 193-199. doi: 10.1177/1948550611415694.

Abstract: “This study found that people who suffer from seasonal affective disorder (SAD) displayed financial risk aversion that varied across the seasons as a function of seasonally changing affect. The SAD-sufferers had significantly stronger preferences for safe choices during the winter than non-SAD-sufferers, and they did not differ from non-SAD-sufferers during the summer. The effect of SAD on risk aversion in the winter was mediated by depression.”

 

“Toward Enabling Winter Occupations: Testing a Winter Coat Designed For Older Adults”
Canadian Journal of Occupational Therapy, February 2011, Vol. 78, No. 1, pp. 57-64.

Abstract: “Background. Previous research indicates that older adults have difficulties using winter clothing, which contributes to their risk of isolation during winter. Research has also shown that a winter coat that requires less flexibility, strength, and dexterity would help support this population. Purpose. This pilot study evaluated the measured and perceived effectiveness of a winter coat prototype that had a funnel sleeve design. Methods. Eight older adults trialed three coats (the participant’s own coat, a coat fitted with sleeve gripper, and the prototype coat), which were evaluated though shoulder range of motion measurements and by the participant completing a survey. Findings. Less shoulder range of motion was used to put on the prototype coat. Survey findings support range of motion data that Sleeve Gripper has limited utility. Implications. A funnel sleeve design may require less range of motion at the shoulder compared to other coats.”

 

“Seasonal Variations in Blood Pressure: A Complex Phenomenon”
Journal of Hypertension, July 2012, Vol. 30, No. 7, pp. 1215-1320. doi: 10.1097/HJH.0b013e328355d7f9.

Abstract: “Seasonal variations in cardiovascular morbidity and mortality show a winter peak and summer nadir, as reported since decades across different latitudes, ethnic groups and age strata. Mortality excess in winter months is mostly related to cardiovascular events including acute myocardial infarction, sudden death, stroke and pulmonary thromboembolism. In a landmark study based on 300,000 cardiovascular deaths from the Canadian Mortality Database, Sheth et al. observed a 19 and 20% increase in mortality, respectively, from acute myocardial infarction and stroke, in January compared with September. In a community-based study carried out in Minnesota, USA from 1979 to 2002, a 17% increase in sudden cardiac death was found in winter compared with summer.The association between cold weather and sudden death was similar over years, across age and sex groups and was stronger for individuals without a previous history of coronary heart disease. Available data are mostly derived from countries exposed to cold/temperate climates characterized by large variations in seasonal temperature. Similar findings, however, have been also reported by studies performed in countries with smaller variations in environmental temperature. In a population of almost 1 million persons in Israel, mortality from ischemic heart disease and stroke in men was, respectively, 51 and 48% higher in mid-winter than in mid-summer; the corresponding figures in women were 48 and 40%, respectively. Seasonal variations have been also reported for nontraumatic rupture of thoracic and abdominal aortic aneurysms.”

 

“Explaining Unequal Participation: The Differential Effects of Winter Weather on Voter Turnout”
MIT Political Science Department Research Paper No. 2011-13, 2011.

Abstract: “Understanding how economic inequality translates into unequal political participation is critical, as the consequences of such inequality-unequal influence over political outcomes – are so acute… When individuals in a state [suffer] unexpectedly cold winters, all state residents will experience a shock to their costs of living, but low income residents will be more vulnerable to these shocks. As a result, the opportunity costs of political participation are higher for low income residents, which can influence their voting behavior in an approaching election. These same costs are probably negligible for more financially-secure residents. Using voter data from the American National Election Study in conjunction with state-level temperature data for the years 1952 to 2004, this analysis finds that deviations from average state temperatures in January have a significant impact on voting in the election the following November, but only among low income respondents. These findings hold up to various model specifications and sensitivity tests.”

 

Tags: research roundup, municipal, safety, aging, senior citizens, disabled

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