Clinical Trial Details
— Status: Active, not recruiting
Administrative data
| NCT number |
NCT05256212 |
| Other study ID # |
0167-17-ASF |
| Secondary ID |
|
| Status |
Active, not recruiting |
| Phase |
|
| First received |
|
| Last updated |
|
| Start date |
August 15, 2017 |
| Est. completion date |
December 31, 2024 |
Study information
| Verified date |
January 2023 |
| Source |
Assaf-Harofeh Medical Center |
| Contact |
n/a |
| Is FDA regulated |
No |
| Health authority |
|
| Study type |
Observational
|
Clinical Trial Summary
The aim of the current trial is to assess the exposure of firefighters (FF) to environmental
pollutants emitted from fires, to explore the association of exposure with their health
status and to compare these data with those of non-FF participants
Description:
Occupational exposure of firefighters to environmental contaminants Background Firefighters
(FF) are exposed during their firefighting activities to a vast array of contaminants and
toxic gases vapors that are released into the environment as results of combustion. Between
those materials, there are heavy metals, brominated flame retardants (Polybrominated diphenyl
ethers, PBDEs) and Volatile organic Compounds (VOC) that include between others Benzene,
Toluene, Ethylbenzene and Xylene (BTEX).In the last decade a concern for negative health
impact for all these contaminants appeared.
There is a vast use of these materials in the production of cars, furniture, electrical
appliances, mattresses, paints, etc. These materials are released into the environment and
absorbed by the human body.
There are some groups with increased exposure to these materials in comparison to the general
population, as results of occupational exposure. Some of these groups include FF, workers who
recycle electronic equipment and furniture manufacture workers.
Purposes:
1. to measure the levels of PBDEs, heavy metals and BTEX metabolites in the blood and urine
of FF who are exposed to fires during their work
2. to evaluate the association between the levels of these materials and the health status
of the participants. This will be done using a health questionnaire and the results of
blood tests showing liver, renal and thyroid functions.
3. to compare their exposure levels and health status with those of general population
This is a prospective observational trial in a FF group. Exposure data from the activity log
for each of the FF will also be collected.
Bromide flame retardants PBDEs
These materials are added during the manufacture process to many products such as: plastic,
textile, furnitures, mattresses and electric equipment in order to reduce their flammability.
There are 5 main groups of flame retardants and more than 75 different kinds. BSEF (2006)
reported the highest consumption of decaBDE at 65.7 kt in 2002, The wide manufacture and use
of PBDEs increases their release and their accumulation in the environment with time.
Although PBDEs increase the safety of products in times of fire, they can release unwanted
byproducts such as: dibenzene dioxinbromide and dibenzenofuran bromide.
During the last years, there is an increasing concern re. the nocive effects of these
materials when they accumulate in the body.
Earlier animal studies show toxic effects of flame retardants: developmental neurotoxicity,
hormonal effects and morphological renal and liver changes.
Additional studies show effects on sex hormones, ano-genital distance, puberty onset and
spermatogenesis.
VOC-BTEX: these are aromatic hydrocarbon compounds, widely used in industry. They are a
significant part of the air pollutants.
They have low boiling point and their main way of exposure is via the air. Humans are exposed
to them from different sources: cleaning products, paints, solvents, cosmetics, car exhaust
gases and cigarettes smoking.
Exposure to VOC can increase risk of congenital malformations, neuro-cognitive impairment,
asthma and cancer.
During combustion, VOC are released into the environment. They may harm many systems in the
body: neural, respiratory, reproductive. They also harm the liver and are mutagenic and
immunotoxic.
Heavy metals (HM)
Humans are exposed to HM via the air, water or food. At high levels, all HM can harm the
lungs. Some of the HM are more harmful than others:
Lead -Pb is known for neurological and cognitive harmful effects. Can also harm red blood
cells, aminoacids metabolism and other metabolic systems.
Mercury -Hg can harm CNS, kidneys and embryos. Short exposure at high levels may harm: lungs,
blood tension and heartbeat, digestive system, skin and eyes.
Cadmium- Cd causes abortion and preterm deliveries and can cause acidosis. Chromium-Cr:
hexavalent chromium may cause skin, eyes and respiratory problems. Chronic exposure can cause
cancer.
Study Plan
1. Trial population
FF will be recruited (200). Exposure levels will be assessed for each participant by
means of a detailed questionnaire. Levels of HM, PBDEs and BTEX found in blood and urine
will be evaluated against health parameters such as: liver, renal and thyroid function,
considering demographical , occupational and health variables (age, tenure, known
diseases, eating habits, smoking and drinking.
2. Data and specimen collection
From each FF, urine and blood (30 cc) samples will be collected and keep refrigerated
till arrival into the lab. Samples will be separated and the ones for pollutants
analysis will be kept in deep freezer (-80C) till analyzed.
3. Questionnaires FF will fill up specific questionnaires regarding demography, life-style,
life habits during non-working hours. Basic health status, chronic diseases related to
thyroid, fertility, psychological problems, both prescription and non-prescription drugs
use.
4. Occupational data General data is routinely collected at the FF station such as work
procedures, drills, number of calls.
In addition, personal data will be collected for each FF: tenure, shifts/year, fire
calls or other calls/year, task at the station , etc.
5. Lab tests:
Thyroid function: the following will be tested: 4-FT4; TSH; TPO-Ab Tg-Ab at Shamir MC central
Lab using SOP Renal function: creatinine and GFR will be measured. Liver function: AST and
ALT will be measured
PBDEs will be measured by GC-MS BTEX metabolites will be measured by LC-MS/MS Heavy Metals
will be measured by ICP-MS
As a control group, samples collected in 12/12 trial (NCT03084445) that were not yet analyzed
will be used. These samples were collected from men arriving to Shamir MC delivery room with
their spouses.
