Code Red Extreme Heat in Baltimore

   It’s Code Red Extreme Heat Season and we’re in for a hot summer! Baltimore’s Code Red Extreme Heat response is a multi-agency effort to address the impact of extreme heat on residents. This year, Baltimore has experienced a total of 10 extreme heat days – eight of which occurred in July – the hottest month of the year. Have you ever wondered what a code red day means for your health? 

   Code Red Extreme Heat Alerts are issued by the Baltimore City Health Department (BCHD) when the heat index is expected to reach 105˚F or higher. That’s hot! Heat index is a measure of air temperature and relative humidity that indicates how hot it feels outside. Air quality may also factor into the decision for a local health department to issue an extreme heat alert. Any day where the heat index reaches 95˚F or higher and air quality is unhealthy for sensitive groups – can also trigger a code red alert.  

   “Excessive heat is the leading weather-related killer in the United States. The effects of extreme excessive heat are exacerbated in urban areas related to population density and the heat island effect due to construction and asphalt. Extreme heat is particularly dangerous to young children, older adults, and those with chronic medical conditions.” according to Baltimore City’s Commissioner of Health – Dr. Letitia Dzirasa.  

   Extreme heat impacts both outdoor and indoor air quality. Air quality is both a public health issue and an environmental justice concern as the urban heat island effect results in higher heat-related illnesses for marginalized communities. The Air Quality Index or AQI is used by EPA, state and local health departments to assess the health risk associated with air contaminants. Pollutants which determine a region’s AQI include ground-level ozone (O3), particulate matter (both PM2.5 and PM10), carbon monoxide (CO) and sulfur dioxide (SO2). These pollutants are also regulated under the Federal Clean Air Act (CAA).   

    Air quality is measured on a scale from 0 to 500. The image below shows how various colors correspond to different air quality ranges. An AQI of 100 or lower is typically deemed safe for everyone. AQIs above 100 have varying levels of risks depending on a person’s susceptibility to air quality-related health events. Red corresponds to AQIs above 151 – during which time everyone is at risk of air quality-related complications. These measures are based on a network of air monitoring devices nationwide. You can click here to receive local AQI data for Baltimore City or here to compare the Baltimore to regions other areas across the country.  

   While monitoring for outdoor air quality is important, indoor air quality or IAQ can also pose a risk to human health. EPA’s Indoor Environment Division (IED) notes that historically marginalized communities may be exposed to more indoor irritants, asthma triggers and pollutants. Often, IAQ can be worse than the air we breathe outside due to poor. This can be due to a lack of ventilation in homes, the burning of flammable materials such as gas or wood and smoking. Unlike ambient air, indoor air quality is unregulated leaving many vulnerable populations including children and the elderly exposed to potential health risk from their very own homes’ in school and even in the their workplace. Considering many people spend more than 90% of their time indoors, we have provided helpful tips to make sure you are breathing clean air indoors!