Health damage from exposure to wood dust
Explore health risks associated with wood dust exposure, including nasosinusal cancer. Learn about affected professions and warning symptoms for effective prevention.
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Exposure to wood dust is a significant occupational risk in various industries, with the most serious consequence being cancer of the nasal cavity and paranasal sinuses (adenocarcinoma of the nasal fossae and paranasal sinuses), especially associated with hardwoods. It is crucial to understand the types of wood and at-risk activities for effective prevention.
Types of Wood and Exposed Workers
Botanically, plants are divided into gymnosperms and angiosperms. Gymnosperms, mostly conifers, are generally known as softwoods. Angiosperms include deciduous trees, designated as hardwoods. The classification of "hard" or "soft" refers to the species of the tree and not necessarily its density.
Workers in various areas are exposed to wood dust, whether they are:
- Gymnosperms: mainly conifer dusts (softwoods).
- Angiosperms: deciduous tree dusts (hardwoods).
At-Risk Population and Dust Composition
Both hardwoods and softwoods are widely used in sectors such as furniture manufacturing, carpentry, forestry, sawmills, and plywood manufacturing. Wood dusts are complex substances whose composition varies with the tree species, consisting of cellulose, polyoses (hemicellulose), lignin, and other lower molecular weight substances.
The International Agency for Research on Cancer (IARC) classifies hardwoods in Group I of carcinogenic agents for humans. This classification includes 34 types of hardwoods, such as birch, poplar, oak, and teak. Among the most common softwoods are spruce, cedar, pine, and redwood.
At-Risk Activities
The risk of developing "malignant neoplasm of the nasal cavity produced by exposure to hardwood dust" is associated with several professional activities, including:
- Furniture manufacturing
- Tree felling
- Sawmills
- Wood grinding in the paper industry
- Wood modeling
- Wood pressing
- Machining and assembly of wood parts
- Wood finishing (plywood and chipboard)
- Sanding of parquet polymers, floors, etc.
Risk Factors
The main risk factors for nasosinusal neoplasms are:
- Occupational exposure: Inhalation of wood dust, metal dusts (nickel, chromium, aluminum), work with tanneries and alkaline batteries.
- Tobacco.
- Viral exposure: Human Papillomavirus (subtypes 6, 11, 16, and 18).
- Chronic sinusitis.
Health Effects
Exposure to wood dust can cause respiratory symptoms and diseases. The most serious consequence is cancer of the nasal cavity and paranasal sinuses. When hardwood dusts are mixed with others, the applicable exposure limit value is that of hardwoods.
Additionally, work in the wood industry can cause:
- Rhinoconjunctivitis
- Urticaria and angioedema
- Asthma
- Extrinsic allergic alveolitis
- Reactive airway dysfunction syndrome
- Diffuse interstitial fibrosis
The IARC classified wood dust in group 1 of carcinogenic agents, indicating a strong relationship between exposure to these dusts and the appearance of adenocarcinomas in the nasal fossae and paranasal sinuses. This type of cancer is almost exclusively linked to occupational activity, and its incidence can be controlled by preventive measures.
Epidemiology
Nasosinusal neoplasms are rare, representing 0.2-0.8% of all malignant tumors. Nasosinusal adenocarcinomas are less frequent (8-25%) and, in Portugal, their incidence is 0.19 cases/100,000 inhabitants/year.
These adenocarcinomas are mostly located in the ethmoidal region and the upper part of the nasal fossae (85%), being less common in other cavities. The average age at diagnosis is 60 years, and the male-to-female ratio is 4:1. More than 90% of ethmoidal adenocarcinomas are related to wood dust exposure, with no such association observed with squamous carcinomas in the same location.
In terms of cancer risk, it is not considered relevant to distinguish between the nature (hard or soft) or the granulometry of the wood. The risk increases with the inhalation of formaldehyde, glues, and solvents. People exposed to wood dust have a 500 times higher risk than the unexposed male population and almost 900 times higher than the general population. More than 90% of those affected were exposed for more than five years, with an average latency period of 40 years.
Clinical Picture and Diagnosis of Nasosinusal Adenocarcinoma
Initially, the disease is asymptomatic or manifests with symptoms similar to chronic sinusitis, allergies, or nasosinusal polyposis. The most common symptoms include:
- Nasal obstruction
- Pressure or pain in the paranasal sinuses
- Rhinorrhea (nasal discharge)
- Epistaxis (nasal bleeding)
- Anosmia (loss of smell)
The persistence of these symptoms, or their unilateral manifestation, should raise suspicion of possible malignancy. In advanced stages, symptoms may include pain, continuous tearing, bloody nasal discharge, edema, and displacement of the eyeball, among others.
In cases of tumor location in other regions, symptoms such as anesthesia, paresthesias, maxillary or mandibular pain, difficulty opening the mouth, and dental changes may occur.
These tumors have a low tendency to develop lymphatic or distant metastases (less than 5%). Diagnosis is often made in advanced stages. Suspicion should arise in the presence of nasal obstructive syndromes, facial pain, unilateral and persistent rhinorrhea or epistaxis, which do not respond to usual treatments and require evaluation by an otolaryngologist.
The prognosis for these tumors is reserved, with a 20-50% five-year survival rate, significantly decreasing in cases of intracranial invasion.
Signs and Symptoms to Watch For
- Unilateral nasal obstruction
- Changes in taste and smell (partial or total loss)
- Unilateral and repeated nasal bleeding
- Unilateral seropurulent nasal discharge
- Persistent unilateral facial pain
- Persistent unilateral tearing