In The Lancet 9-11 Anniversary Issue, experts in a variety of fields reflect on the events of 9/11, with original research, review and opinion pieces on the short-term and long-term physical, mental and public health consequences of the terrorist attacks. The research papers report on not only U.S. domestic health effects but some of the international consequences.

Study Shows World Trade Center-Exposed NYC Firefighters Are 19% More Likely to Have Cancer.
A higher proportion of World Trade Center-exposed New York City male fighters have been diagnosed with cancer compared to both their non-exposed colleagues and a comparable sample of the New York City general population, according to this study. 263 cases of cancer occurred compared with 238 expected from the general population data. In the non-exposed group, 135 cancers were diagnosed compared with 161 expected from the general population. The findings are reported in an article by Dr. David J. Prezant, Chief Medical Officer of the Fire Department of the City of New York (FDNY), and colleagues from FDNY and Albert Einstein College of Medicine of Yeshiva University and Montefiore Medical Center in New York.

The study involved 9,853 male firefighters, all of whom had health records dating back to well before 9/11. The authors looked at cancer incidence and its potential association with exposure in the first seven years after 9/11. They compared the cancer incidence rates in WTC-exposed firefighters with cancer incidence in non-exposed firefighters, adjusted for age, race and ethnic origin, and secular trends, and with the US National Cancer Institute Surveillance Epidemiology and End Results (SEER) reference population.

In the WTC-exposed group, 263 cases of cancer occurred compared with 238 expected from the general population data. In the non-exposed group, 135 cases occurred compared with 161 expected from the general population. When cancer incidence in the WTC-exposed FDNY firefighters was compared with the cancer incidence in the general male population in the USA with a similar demographic mix (using standardised incidence rations [SIR]), WTC-exposed FDNY firefighters were at 10% increased risk of having any cancer. When the cancer incidence in WTC-exposed FDNY firefighters was compared with WTC-non-exposed FDNY firefighters, the increased cancer risk (adjusted for surveillance bias) for exposed firefighters was 19%. That the non-exposed firefighters had lower cancer rates than the general population is no surprise, and is likely due to the healthy worker effect: FDNY firefighters have lower smoking rates, stringent pre-employment health requirements, and greater physical fitness standards than the general population.

The cancer incidence for WTC firefighters at specific sites in the body was not significantly increased when compared to site-specific cancers among non-exposed firefighters and the general male population. This failure to reach statistical significance may have been due to small sample size. A trend towards increased risk was, however, noted in 10 of the 15 sites studied (stomach, colon, melanoma, prostate, thyroid, non-Hodgkin lymphoma, bladder, kidney, pancreas, oesophagus). Surprisingly, however, the authors noted 58% lower rates of lung cancer in WTC exposed participants than in the general population, and there appeared to be no increased risk of lung cancer for exposed firefighters versus those not exposed. The authors noted that all nine WTC firefighters with lung cancer were smokers.

The authors say: “An association between WTC exposure and cancer is biologically plausible, because some contaminants in the WTC dust, such as polycyclic aromatic hydrocarbons, polychlorinated biphenyls, and dioxins, are known carcinogens. Although some contaminants could cause cancer directly, WTC exposure could also trigger chronic inflammation, through microbial infections, autoimmune diseases, or other inflammatory disorders, all of which have been reported as factors in oncogenesis, both experimentally and epidemiologically.”

They conclude: “Our findings support continued monitoring of firefighters and other WTC-exposed cohorts to fully assess cancer risk related to these unique exposures.” Read the full article in The Lancet.

Rescue and Recovery Workers Continue to Suffer a High Burden of Physical and Mental Illness.
More than 50,000 rescue and recovery workers are estimated to have given assistance after the World Trade Center (WTC) attacks. Data gathered from more than 27,000 of these workers shows that this unique population continue to suffer a high burden of physical and mental illness. The findings are reported in an article written by Dr. Juan P. Wisnivesky and colleagues of Mount Sinai School of Medicine in New York.

The researchers looked at various conditions among 27,449 participants enrolled in the WTC Screening, Monitoring, and Treatment Program, a federally funded program that provides regular physical and mental health examinations to WTC rescue and recovery workers.

The enrolee’s 9-year cumulative incidence of asthma was 28%, sinusitis 42%, and gastrooesophageal reflux disease (GERD) 39%. Their 9-year cumulative incidence for spirometric abnormalities was 42%; three-quarters of these abnormalities were low forced vital capacity. The authors say: “Inhalation of toxic, highly alkaline dust (pH=10–11) is the probable cause of upper and lower respiratory injury in rescue and recovery workers.”

In rescue and recovery workers, cumulative incidence of depression was 28%, PTSD 32%, and panic disorder 21%. In police officers, cumulative incidence of depression was 7%, post-traumatic stress disorder 9%, and panic disorder 8%. The authors say: “Previous studies have shown that New York City police officers were at lower risk than some responders for developing mental health disorders after the WTC attacks. Possible reasons for these findings include training, previous experience in dealing with similar stressors, self-selection of individuals with high resilience during recruitment into the workforce, and possible under-reporting of psychological symptoms because of perceived job-related repercussions.”

The authors conclude: “Our findings show a substantial burden of persistent physical and mental disorders in rescue and recovery workers who rushed to the site of the WTC and labored there for weeks and months 10 years ago. Many of these individuals now suffer from multiple health problems. The findings of this study emphasise the need for continued monitoring and treatment of the rescue and recovery worker population and underscore the importance of providing adequate health monitoring and treatment for these individuals. Planning for future disasters should anticipate the probability of persistent physical and mental illness in rescue and recovery workers.”

Lancet 2011; 378: 888–97