The Hazards/Cancer Puzzle

There is already enough evidence that pollution causes cancer. We already have enough information on the contaminants in our air, our water, our soil, products that we use, and food that we consume to know that we must work toward eliminating the sources of our exposures to carcinogens.

But we want, and need, to know more. Turneret al., in their review article on outdoor air pollution and cancer (2020), revealed that:

“there is substantial evidence from studies of humans and experimental animals as well as mechanistic evidence to support a causal link between outdoor (ambient) air pollution, and especially particulate matter (PM) in outdoor air, with lung cancer incidence and mortality” (par 1).

“Epidemiological evidence for associations of outdoor air pollution with types of cancer other than lung cancer is more limited, although adverse associations have been reported in an increasing number of studies” (par 24).

The article describes epidemiological evidence linking outdoor air pollution with cancer incidence and mortality, and it describes biological mechanisms of air pollution-derived carcinogenesis. The authors suggest dozens of public health and public policy recommendations for interventions to reduce outdoor air pollution levels, including urban design factors, public transportation, raising public awareness, and the monitoring of local air quality indices and guidelines. The authors go on to recommend that, while we are attending to the immediate and urgent need for research on specific interventions for cancer prevention, further research on cancer incidence and survival is needed.

We still need to Connect the Dots

We – as a nation and world – are getting better at being able to identify, measure, and reduce environmental hazards (the first piece of the puzzle), and our tumor registrars and statisticians are doing a great job of accurately recording the cancers according to address at diagnosis (the last piece of the puzzle).

If residents and industries remained in the same place from birth until death, we might have a better handle on pollution-related causes of cancer. Maps would tell us: here’s the industry, these are the chemicals being emitted, and here are the people that have been diagnosed with cancer.

But the people in the White Lake area did not stay in one place. Cancer incidence statistics may have underrepresented cancers that occurred years to decades after the pollution had occurred because people had moved away.

To solve the hazards/cancer puzzle and to prevent cancers in the future, we must figure out the middle parts. How long are the latency periods between onset and diagnosis for each cancer type? How can we keep track of a person’s environmental exposures over time? Could biomonitoring provide clues?

Ideas and Hopeful Signs of Progress

While researching for this cancer project report, I came across some ideas and, in some cases, hopeful signs that we are on the cusp of having technology that will help us reduce our cancer burden.

The President’s Cancer Panel 2008-2009 Annual Report recommended that “Physicians and other medical personnel should routinely query patients about their previous and current workplace and home environments as part of the standard medical history” (p. xvii) to strengthen the body of information on environmental exposures and cancer. Data on workplace and home environmental history should be incorporated into Electronic Medical Records (EMR) systems (which were emerging at the time of the 2009 report).

Now we are increasingly seeing the use of Electronic Health Records (EHR), which can provide a mechanism for closing the environmental health gap by incorporating exposure histories into them. The Agency for Toxic Substances and Disease Registry (ATSDR) provides information on how primary health providers could play a role in detecting, treating, and preventing disease resulting from toxic exposures.

The ATSDR proposes three components to establishing and maintaining an Exposure History for individuals: 1) Exposure Survey, 2) Work History, and 3) Environmental History. The ATSDR provides an Exposure History Form, available for download in a “fillable” PDF format.

Individuals who believe that they have been exposed to contaminants could be proactive by using the Exposure History Form as a tool to let medical personnel know of their possible exposures. Bringing their completed form to their doctor or to a major medical facility could add credibility to their concerns and could be incorporated into their Electronic Health Record.

According to Ohayan et al. (2020), in breast cancer organizations, references to environmental chemicals are infrequent. Most organizations (82%) discuss other risk factors like exercise, diet, family history, or genetics. Four barriers to addressing environmental chemicals are listed: “time and resource constraints, limited knowledge of the state of the research …, difficulties with messaging …, and institutional obstacles, such as the downplaying of environmental risks by industry interests” (par 3).

We can learn from, and support, non-governmental organizations that educate about environment and health and advocate for healthier environments. They include:

Environmental Working Group

Natural Resources Defense Council

Silent Spring Institute

National Foundation for Cancer Research

Collaborative on Health and the Environment

Safer Chemicals, Healthy Families

We can also take notice when cancer organizations fail to include information about cancer prevention and environmental contaminants in their mission statements and their work, and then contact them to tell them of our concern.

We need more research on latency periods for various types of cancer, to help us estimate when an exposure of a person diagnosed with cancer was likely to have occurred. Although research into latency times between initiation and diagnosis is still in its infancy, researchers are trying to study this complex subject by proposing models of carcinogenesis and studying cell biology for clues about cancer initiation and progression.
The Centers for Disease Control and Prevention’s Division of Laboratory Sciences has a National Biomonitoring Program that assesses people’s exposure to chemicals that may be toxic and responds to environmental health issues. This involves measuring environmental chemicals or their breakdown products in human tissues and fluids, such as blood and urine.
The National Cancer Institute (NCI) provides information on research that is being done on Causes of Cancer. NCI’s initiative, Precision Prevention: Predicting and Intercepting Your Cancer, aims to study inherited cancers that run in some families, testing individuals at targeted ages, before their cancers can develop. They then hope to apply what they have learned to the general population. This initiative mentions technologies that make collecting data less costly and less burdensome, like wearable sensors and telemedicine tools, and figuring out how to integrate imaging technologies with biomarker testing.
Rare cancers present challenges to patients and their families. Although the NCI’s Cancer Moonshot program (2016, reignited in 2022) focuses on treatments for cancer, rather than on cancer prevention, several of their initiatives are likely to provide specimens and data that would be valuable for cancer prevention research and for research on rare cancers. Two examples are the Cancer Moonshot Biobank, in which participants donate samples as they receive treatment to help researchers learn more about cancer, and My Pediatric and Adult Rare Tumor Network (MyPART), in which information and biospecimens are collected from people or the relatives of people with rare tumors to help researchers learn more about how rare tumors grow and develop.
Case-control studies of the populations immediately surrounding polluting industries (rather than studying populations according to ZIP code or census tract) would help to confirm the connections between the industrial hazards and the cancers. Only then could industries be held accountable not only for cleaning up the environment but also compensating their victims, which would be an incentive to operate in a manner that is safe for workers, neighbors, and consumers of their products.

A series of population-based multicase-control studies studies (MCC–Spain) laid the groundwork and methodology for connecting some dots in Spain by studying people living in the immediate vicinity of polluting industries. These are detailed in the section “Proximity to Industry as a Risk Factor” in this report.

Longitudinal studies are needed, such as the University of Michigan’s Michigan Cancer and Research on the Environment Study, MI-CARES, which will enroll 100,000 participants who live in environmental hotspots throughout Michigan, who will be followed over time through surveys as well as blood and saliva samples to track environmental exposures and cancer biomarkers.

The National Institutes of Health’s All of Us Research Program hopes to gather health data from one million or more people of diverse backgrounds living in the United States to accelerate research that may improve health. The research focuses on the interaction of three factors: environment, biology, and lifestyle. All of Us is focused on health in general and is not specifically focused on cancer, but this program will provide a rich data resource, including biospecimens and increasingly robust electronic health records, that could lead to research breakthroughs in causes of cancer.

Follow-up studies on large-scale disasters are occurring, such as the Chernobyl disaster and thyroid cancer, the 9/11 attack on the World Trade Center and Minimum Latency research, and Veterans’ Diseases Associated with Agent Orange.
Maps are powerful. Maps such as those listed below should prompt researchers to conduct population-based case-control studies to learn the details: what are the cancer risks within ¼ mile from the pollution source (and ½ mile, 1 mile…) and what contaminants are contributing to the studied types of cancer.

The Air Toxics Screening Assessment (AirToxScreen) is EPA’s screening tool to provide communities with information about health risks from air toxics. AirToxScreen has a mapping tool for interested users.

ProPublica published The Most Detailed Map of Cancer-Causing Industrial Air Pollution in the U.S. by Al Shaw and Lylla Younes, November 2, 2021 (additional reporting by Ava Kofman).

The New York State Environmental Facilities and Cancer Map shows 1) the number of people diagnosed with cancer (cancer counts, 2011-2015) in small geographic areas of New York State, 2) highlighted areas where cancer is higher or lower than expected, and 3 ) the locations of certain environmental facilities.

Citizens can make their own maps. In Sacrifice Zones (2010), some citizens used government resources to quantify the chemicals released in their community, then created maps showing the location of the releases, the wind direction at the time of the releases, and the citizens’ exposure and symptom logs. When these maps were shown to community members, they were galvanized into taking action – to speak up to demand their rights to clean air.

My Takeaway

After looking at these data for a decade, here are my thoughts on options for filling in the gaps between the hazards and the cancers.

We need intelligence-oriented Electronic Health Records (EHR), programmed for ease of use so as not to overburden medical personnel with more work and designed with “Big data analytics systems.” These systems would “aggregate very large amounts of health and health care data to compare the effectiveness of treatments, identify medication and device safety problems, facilitate medical discovery, and analyze shifting patterns of patient characteristics and diseases.” (Glaser, 2020, par 33).

Patients’ EHR should include patient Residence Histories going forward (just don’t delete previous addresses when patients move) and Exposure Histories that include the following components: 1) Exposure Survey, 2) Work History, and 3) Environmental History. (Agency for Toxic Substances and Disease Registry – ATSDR). The ATSDR provides a sample Exposure History Form.

We need BioBanks, as described in the Cancer Moonshot Biobank program in which people with cancer donate blood and tissue samples during their treatment. BioBanks are also being used in longitudinal studies such as the Michigan Cancer and Research on the Environment Study (MI-CARES), in which participants from diverse racial and ethnic backgrounds who live in environmental hotspots “will be followed over time through surveys as well as blood and saliva samples to track environmental exposures and cancer biomarkers” (par 4). The former program focuses on discovering effective cancer treatments, while the latter study seeks to “describe and quantify the impact of known and suspected environmental exposures on cancer risk” (par 2). Both acknowledge biomonitoring as an essential component in our quest to prevent and treat cancer.

Intelligence-oriented EHRs that include Residence Histories and Exposure Histories, linked with a Biobank, could go a long way toward providing researchers the data they need in their work to connect the dots between exposures and cancer.

This may be costly, but what is the cost of not doing this research?