|Recently, cold and wet weather are associated with cancer risks / Photo Credit: Tawatchai Prakobkit via 123rf|
A study published in the journal Environmental Engineering Science found a link between wet and cold weather and cancer prevalence.
Science has previously detailed that one of the causes of cancer is environmental exposure. For instance, exposure to UV radiation, radon, and fine particulate matters can cause cancer. The recent study, however, pointed the blaming finger to the cold weather and precipitation.
Authors Vishal Shah from the West Chester University of Pennsylvania and team said that they tested their hypothesis that climate zone and precipitation play a role in determining the incidence rate of cancer in the US by using the country-level cancer incidence rate data provided by the Centers for Disease Control and Prevention as a part of the National Program of Cancer Registries Cancer Surveillance System.
Climate factors increase the biotic generation of carcinogens
The team then developed an individual, generalized linear model for every separate cancer incidence rate and the total invasive cancer. The authors considered climate zone as a combination of moisture level and temperature in a given area. While they did not suggest that increased moisture, temperature, and rainfall caused cancer directly, they explained that these climate factors can increase exposure to carcinogens. This is because these factors serve as the carriers that increase the natural biotic generation of the carcinogens.
|Increased rainfall drains away elements, such as potassium and magnesium, from the soil / Photo Credit: Irina Schmidt via 123rf|
Rain is making the soil more acidic
Another theory that the authors explained focused on the East Coast that gets more rain than anywhere else in the US. They said that increased rainfall drains away elements, such as potassium and magnesium, from the soil. As a result, it makes the soil more acidic. This creates a ground for ammonia-oxidizing bacteria that changes the ammonia into nitrites. When released into the atmosphere, nitrites become nitrous acid that health authorities consider as a carcinogen.
Overworked metabolism in colder climates
Researchers also mentioned about overworked metabolism in colder climates as the body experiences metabolism stress and tries to maintain the body temperature. “There is a statistical relationship between incidence rates of cancers in a given area and the amount of precipitation and climate type,” the team concluded.
Health news provider Medical News Today also reported that Shah and colleagues’ research was the first study in the US to ever consider the link between climate zone, precipitation, and cancer rates. Scientists in the study collated the data on prostate cancer, colorectal cancer, lung cancer, ovarian cancer, and breast cancer to investigate. They also used the country-level data of demographics, climate, and cancer prevalence. Since the datasets came in large sizes, they opted to study 15 states randomly. These were Wisconsin, Washington, Texas, Utah, South Carolina, Oklahoma, Massachusetts, New York, California, New Jersey, Iowa, Georgia, Connecticut, Arkansas, and Arizona.
The authors also adjusted their study analysis to control for diversity, population age, income level, ethnicity, gender, and age because these can influence the population’s cancer rates. After making the necessary adjustments, they found a strong association that showed increased precipitation in a place also increases the incidence of all cancers. In the same way, climate zone was also linked to cancer outcomes.
Limitations of the study
The overall cancer incidence rates were higher in regions that are very cold than areas with dry and hot climates. Yet, the group broke cancer in two types and highlighted exceptions. For example, lung cancer occurs more in dry and hot zones. There are also certain limitations in the study, such that they only analyzed 15 states. This means that the pattern may not be the same as in other states or countries. They said that as it is the first study of its type, there is a need for further research to back up what they found.
Cancer facts and figures 2019
Voluntary organization The American Cancer Society detailed the most common cancer types in the US this year. In men, they include prostate (174,650 new cases, 20%), lung and bronchus (116,440, 13%), colon and rectum (78,500, 9%), urinary bladder cancer (61,700 , 7%), and melanoma of the skin (57,220, 7%).
The most common cancers in women, on the other hand, are the following: breast cancer (268,600 new cases, 30%), lung and bronchus (111,710, 13%), colon and rectum (67,100, 7%), uterine corpus (61,880, 7%), and melanoma of the skin (39,260, 5%).
The American Cancer Society added that 80% of all cancer cases in the US are diagnosed in people who are 55 years of age or older. Particular behaviors likewise increased risk, such as drinking alcohol, having excess body weight, and smoking. In the United States, 39 out of 100 men and 38 out of 100 women will develop cancer during their lifetime, and it usually happens among older people. The organization has estimated the probabilities based on the cancer occurrence in the general population but said that it may be an underestimate or overestimate if based on individual risk considering the differences in exposures, family history, and one’s genetic susceptibility. The 2019 estimate does not include noninvasive cancer of any site except urinary bladder. It also does not include squamous cell skin cancers.
While the study remained inconclusive, it nevertheless gave some valuable insights into how our surroundings play an important role in our overall health. For this reason alone, taking care of our environment becomes an even bigger mission for us.