Health Impacts

Health status and patterns of disease are influenced by at least four main factors, including social-economics, health behaviors, clinical care, and the physical environment.  Weather and climate have important influence on our health, and we have learned much about how a changing climate may affect our health and wellness.

Our State’s Health

NH DHHS have begun to explore the available data, gaps in knowledge, and have significant expertise in this area of health.  In addition, we have completed original studies in the state on the specific health impacts of weather and climate hazards.  The three main areas of health concern with the best data and findings include 1) heat injury, 2) traumatic injury, and 3) tick borne disease. Of course, many other weather and climate impacts occur, yet a strong evidence base may not yet available to quantify the impact.

Rising Heat Stress

The number of extreme heat events (i.e. hot days and heat waves) have increased over the past few decades in New Hampshire.  Since 1980, the average number of days with a heat index over 90°F has doubled from 8 days a year to 15 days.   By midcentury, projection models indicate that the annual number of weather events above 90°F may increase by 10 to 30 days, under a higher emissions pathway (2). A recent study of heat stress and related hospitalizations (funded by DHHS/CDC) found that high heat days led to an increase in admission rates for ‘all cause’, and specifically for heat injury, renal/kidney problems, and asthma (3).  The good news is that NH DHHS has developed an extreme heat response plan, and also provides trainings for at-risk older adults on how to avoid and manage heat stress.

Changing Traumatic Injury

The number and intensity of extreme weather events, including high temperatures and heavy precipitation, has increased over the past few decades in NH.  Our extreme weather conditions drive impacts such as heat injury, cold injury, CO poisoning, vehicle accidents, accidental falls (snow/ice), and many other health issues.  A recent NH study of extreme weather and related hospitalizations (funded by DHHS/CDC) found that high temperatures were more strongly correlated with an increase in hospital admissions for all-cause traumatic injury and heat-related injury visits, and less correlated with vehicle accident or accidental falls (4).  The good news is that NH DHHS tracks and works to reduce common injuries, especially among kids, and develops trainings to improve home emergency preparedness for a variety of extreme weather events.

Changing Tick Habitat & Related Illness

The rise in tick abundance and tick-borne disease in the Northeast US is due to many factors, including a changing climate and land uses that fragments the forest. Over the past two decades, the geographic range of disease-carrying ticks (esp. the black legged tick) has expanded substantially, which likely contributes to the increase in human Lyme disease cases. Recent modeling studies indicate that climate factors such as seasonal precipitation and temperature explain much of the change in tick habitat (5,6).  The good news is that we can teach people to avoid tick habitat, wear protective clothing, find/remove ticks, and use repellents wisely.

Other Health Impacts of Weather and Climate

The health topics identified above have the strongest evidence base for weather and climate-related impacts, and have effective prevention strategies. Public health studies can more readily estimate the health impacts of shorter-term weather events, yet it is much more difficult to estimate the health impacts of longer-term climate trends.  For example, research shows the expanding pollen season may have an impact on allergies and asthma.  Other research shows that extreme weather events may have an impact on mental health.  Other research shows that rising ocean temperatures in the Great Bay may increase the risk of food-borne disease in shellfish.  NH DHHS continues to monitor these health impacts within its limited resources and via collaboration with its partners.