Twenty-five years after the 9/11 attacks, the United States commemorates the milestone anniversary as the world reflects on the shock, the lives lost, and the enduring consequences of that day. What sets this year's ceremony apart is the addition of a moment of silence to honour those who were exposed to the toxic dust clouds from the collapse of the Twin Towers and have since died of 9/11-related illnesses.
Reportedly, an estimated 4,10,000 to 5,25,000 people were exposed to toxic dust and hazardous air after the collapse. The toxic cloud of dust contained pulverised concrete, glass fibres, asbestos, lead, and jet fuel soot.
According to the CDC, over 4 lakh people were exposed to toxic contaminants, at risk of physical injury, and physically and emotionally stressful conditions in the days, weeks, and months following the attacks. Even the fires burned in the rubble for over three months, releasing continuous carcinogenic combustion by-products.
Exposure to some of these hazards has been linked to aggravating, contributing to, or causing various short- and long-term health conditions covered by the WTC Health Program, such as:
*Acute traumatic injuries (like burns, sprains, and fractures)
*Aerodigestive (airway and digestive) disorders (like asthma, GERD, and sleep apnea)
*Cancers
*Mental and behavioural health conditions (like PTSD, depression, and substance abuse); and
*Musculoskeletal disorders (like carpal tunnel syndrome and low back pain).
Responders who worked on the rescue, recovery, and relief efforts reported a range of illnesses soon after the attacks. Survivors who lived, worked, and attended school in Lower Manhattan, some who remained throughout and some who returned to their lives in the disaster area, started reporting illnesses as well.
What happens during long-term exposure to toxic dust?
Chronic Respiratory & Lung Diseases: Months of sustained exposure lead to irreversible structural damage, including asthma, Chronic Obstructive Pulmonary Disease (COPD), and Interstitial Lung Diseases (ILDs) like sarcoidosis and pulmonary fibrosis.
Oncological Pathologies (Cancer): Toxic chemical exposure (benzene, asbestos, dioxins) creates DNA mutations with long latency periods. Common long-term diagnoses include prostate, skin, thyroid, and lung cancers, as well as blood/marrow cancers like multiple myeloma.
Cognitive & Neurological Decline: Recent longitudinal studies show that chronic exposure to neurotoxic dust combined with trauma significantly accelerates brain ageing and doubles the risk of early-onset dementia and cognitive impairment.
Systemic Complications: Chronic physical inflammation frequently co-occurs with cardiovascular diseases, persistent autoimmune disorders, and post-traumatic stress disorder (PTSD).
When does the toxic dust really settle?
The settling of the toxic dust depends on whether you look at the immediate physical fallout or the long-term environmental and health impact:
*Ambient air settling (5 Months): The vast majority of the immediate airborne dust cloud settled within hours of the collapse, but dust continued to blow through Lower Manhattan for roughly five months as fires smouldered through December 2001 and heavy machinery agitated the site.
*Site debris clearing (8 Months): The physical debris and settled dust at Ground Zero were officially cleared after eight months, culminating when the final steel beam was ceremonially removed on May 30, 2002.
*Indoor contamination (Years): Uncleaned air ducts, window sills, and internal building systems in nearby Lower Manhattan properties retained toxic particulates—including asbestos and heavy metals—for years until deep professional remediation took place.
*Health fallout (Ongoing): Biologically, the impact of the dust has not settled. Carcinogens like asbestos and dioxins have latency periods ranging from 10 to 30+ years, meaning new cases of 9/11-related cancers, pulmonary fibrosis, and respiratory conditions continue to be diagnosed decades later.
Questions remain about how many people developed health problems linked to the dust.
On September 11, 2001, al-Qaida extremists hijacked four commercial jets and crashed them into New York's World Trade Centre, the Pentagon and a field near Shanksville, Pennsylvania.
