Weekly Contributions

Occupational Lung Disease Recognized through an
Epidemiological Investigation

Bongsoo Jung (Labor
Attorney, KangNam labor law firm)

 

I. Introduction

When an employee applies for compensation for an
occupational illness, the Korea Workers’ Compensation & Welfare Service (hereinafter
referred to as “COMWEL”) determines whether the employee has an occupational illness
or not through its own investigation, the opinions of a medical professional
(or professional agency), and a review by the Occupational Disease Determination
Committee. In cases where its own investigation is unable to determine whether
there is a relationship to work, COMWEL can ask a professional agency to
conduct an epidemiological investigation, through which it will determine whether
the illness in question is an occupational illness or not. Such illnesses as black lung disease (Pneumoconiosis)
and lead poisoning, and conditions such as noise-induced deafness are more
easily linked to occupation than some other illnesses such as cancer, hemoptysis
(vomiting blood), asthma, and dermatitis are not so easy to link. In this case,
gathering information on the working environment will be of considerable help.

I would like to introduce a case of occupational illness
which resulted in death from vomiting of blood. The employee in question had had
a lung illness for a long period of time, and along with severe coughing,
became worse from his harmful working environment. The labor attorney for this
case claimed, on the basis of a statement from his surviving family, that the
industrial illness victim (hereinafter referred to as “the employee”) died from
his long-term illness deteriorating through exposure to harmful chemicals like
sulfuric acid in the process of zinc smelting. The labor attorney submitted an
application for survivor’s benefits without a direct investigation. After receiving
the application, COMWEL asked a professional agency (the Occupational Lung Disease
Research Institute) to conduct an epidemiological investigation. Once the
results were in, COMWEL concluded a close relationship between the employee’s
workplace environment and the exacerbation of his illness, accepting his death
as due to a work-related illness. 

 

II. Summary

(1) The employee had worked at a zinc smelting factory since 2016. When he died at
Aju University hospital at age 61 on December 16, 2021, his spouse applied for Survivor’s
Benefits on February 29, 2022 to the COMWEL Youngju Office.

(2) On December 9, 2021 when
the employee began vomiting blood and experienced difficulties in breathing, he
was admitted to Wonju Christian Hospital where he continued to vomit blood and
suffer from pneumonia. He died from respiratory and organ failure on
December 16, 2021.

(3) Since joining OO zinc smelting company[1] on June 12, 2016, the employee had worked as a machine
operator in charge of a filter press machine for a total of 5 years and 3
months. The smelting process at a filter press extracts zinc by dividing cake (solids)
and filtrate (liquid) after melting sludge coming from a sludge container. The
employee swept up the cake on the floor when it fell in the process of dividing
from the filtrate. In this smelting process, sulfuric acid[2] was used and the employee was continuously exposed to the
sulfuric acid gas.

(4) Before beginning employment at OO company, the
employee had worked as a street cleaner from 2011 to 2015 (aged 51 to 55) from 4
am to 4pm, during which he began suffering from, and receiving treatment for, bronchitis
and obstructive lung disease due to early morning cold air.  

(5) As mentioned, the employee had been exposed to
sulfuric acid gas, mineral dust, etc. continuously at the workplace while
suffering from existing bronchitis and obstructive lung disease. In addition to
this, the employee had to work longer hours than normal for a long period, which,
combined with the stress from worry he would lose his job due to his poor
health, was claimed to have caused pulmonary (lung) hypertension, resulting in
his vomiting blood and ultimately his death.

(6) Fifteen months after his spouse applied for Survivor’s
Benefits, during which COMWEL conducted an investigation, received medical
opinions, and the results of an epidemiological investigation, the Occupational
Disease Determination Committee agreed that the employee died from an
occupational illness.  

 

III. The Limits of Investigation and Request for
Epidemiological Investigation

1. The applicant’s difficulties in investigating for herself

  In
the application for Survivor’s Benefits, the applicant claimed that the employee had suffered from chronic fatigue due to working in two shifts for a long
period of time; had stress and insomnia due to worries over losing his job
because of his illnesses; and had been exposed to a harmful working environment
(including sulfuric acid), which had caused pulmonary hypertension, vomiting of
blood, and his death. The claim that the employee suffered from fatigue and
stress could be causes for stroke or heart disease, but not for vomiting blood. Accordingly, the applicant had to verify that the
workplace’s harmful substance (sulfuric acid) had exacerbated the employee’s
existing conditions of bronchitis and obstructive lung disease and had caused
pulmonary hypertension and vomiting of blood. However, the applicant was not
able to gain access to the workplace, and had to depend on the COMWEL
investigation. The following is the result of the epidemiological investigation
from the professional agency commissioned by COMWEL.

 

2. COMWEL request for an epidemiological investigation

When there is difficulty in
determining whether an illness is occupational or not, COMWEL can ask for
professional opinions from a medical doctors’ advisory council, the industrial
safety and research centers of the Korea Industrial Safety Corporation, or
other agencies that can evaluate occupational diseases.
Also, the Medical Care Processing Rules describe that when it comes to
difficulty in determining recognition of an occupational illness concretely,
COMWEL may ask relevant institutes (such as medical
doctors’ associations or industrial safety research institutes) to give advice
and participate in the investigation. This includes cases 1) where it is
difficult to verify whether the employee’s existing illness affected
the occupational illness, 2)
where meaningful difference exists between the medical doctor in charge and the
advisory doctor regarding clinical signs that will show the degree of the employee’s exposure to
harmful materials, 3) where it is difficult for a doctors advisory council to
determine relation of an illness to occupation, or where there are no criteria for
the occupational illness, and 4)
where an epidemiological investigation is necessary to recognize whether a cause-and-effect
relationship exists between work and illness. Upon concluding this investigation, as long as there is no clear
evidence to disprove the illness was work-related, it should be accepted as an
occupational illness.

3. Epidemiological investigation and recognition of the occupational disease by
the Occupational Lung Disease Research Center

(1) Understanding workplace environment
   The employee’s work was to operate the filter
press (F/P disintegration) machine to retrieve a small amount of metal out of
sludge coming from a sludge container. In this process, the employee was exposed
to steam and carbon monoxide (CO) from the leftover liquid and cake. There is
no artificial ventilation system in the disintegration process of the filter
press, but there is natural ventilation in the roof of the three storey building.
The agency measured the air quality of the workplace twice: on October 10, 2012,
for 5 hours and 40 minutes to check the internal air of the workplace with a
multiple gas measurement instrument; and on March 26 & 27, 2023, for 20
hours to check carbon monoxide concentrations in the air near the filter press,
with a carbon monoxide measurement device. Additionally, workers’ individual
exposure was measured by affixing the measurement instruments to the waists of three
workers onsite for twenty hours.
  The results of measurement showed an
average density of 38ppm of carbon monoxide in the work area around the filter press. At the height the worker was breathing at
the top of the F/P machine, concentrations exceeded 500ppm, the limit of the
measurement instrument. Individual measurement done for 20 hours averaged
19ppm, 60% of the exposure limit according to the Ministry of Labor. However,
as time passed, the density of carbon monoxide increased up to a maximum of 185ppm.
Besides carbon monoxide, hydrogen sulfide was detected at an average of 5.1ppm.

 (2) Effects
of carbon monoxide & hydrogen sulfide on the human body
  The normal concentration of carbon
monoxide is 0.1~0.2 ppm. This carbon monoxide combines with hemoglobin
delivering oxygen to the body, and results in carboxy-hemoglobin, causing hypoxia
(low oxygen levels in the blood). This contracts blood vessels in the lungs and
increases resistance of lung vessel (lung rigidity), which causes pulmonary hypertension.
As mentioned, hydrogen sulfide was also measured at an average of 5.1ppm around
the filter press. If a healthy adult is exposed to hydrogen sulfide up to a
density of 50ppm, pulmonary edema (fluid into the lungs) appears. Exposure to a
density of 5.1ppm of hydrogen sulfide could not cause lung damage, but hydrogen
sulfide just like carbon monoxide is also chemical material to influence lung hypertension.
Accordingly, as the employee had repeatedly been exposed to a high concentration
of carbon monoxide, this mixed exposure to hydrogen sulfide could have affected the occurrence of lung hypertension.   
 (3) Occupational illness

   The employee, who had been exposed to
a density of carbon monoxide since December 2016, experienced headaches and a
decline in physical abilities that could have been due to the carbon monoxide exposure.
Moderate lung hypertension was diagnosed in August 2020, four years after beginning
employment at the zinc smelting company. This had become severe hypertension by
October 2021. Upon reviewing medical records from that time, no diseases were
diagnosed that would be responsible for lung hypertension. It could, however,
have occurred from the repeated exposure to a high density of carbon monoxide in
the course of working at his last workplace, and possibly
from the exposure to hydrogen sulfide. Lung hypertension causes vomiting of
blood. This hemoptysis (vomiting of blood) does not reverse easily, and can
easily reoccur even upon improvement. It was therefore concluded that the
employee died from the vomiting of blood, caused by lung hypertension.
  

IV. Determination of Occupational Illness

Making a determination of whether occupational illness exists or not through epidemiological investigation
requires time and money, but provides objective and scientific processes,
allowing both the employee and the decision-making body to easily accept the findings.
Accordingly, the use of a professional agency to conduct the epidemiological
investigation is recommended, and can help stop further occupational illness in
the early stages by providing accurate data on harmful factors in the workplace.

<Determination of occupational illness>
  1)
According to the epidemiological investigation submitted by the professional
agency that COMWEL commissioned, the employee had been exposed to carbon
monoxide and hydrogen sulfide together, causing lung hypertension which in turn
resulted in vomiting of blood and death. It is therefore determined that the
employee’s death was from occupational illness.
  2) The advisory medical doctor to
COMWEL stated that lung hypertension had been the result of repeated exposure to
a high concentration of carbon monoxide, which had caused acute respiratory
failure and acute pneumonia, leading to death.
  3) The Occupational Disease Determination
Committee reviewed the investigation findings, the examinations submitted by
COMWEL and based on medical opinions, and the measurements of the workplace
environment conducted by the professional agency. The Committee determined that
the employee’s lung hypertension was the result of repeated exposure to carbon
monoxide and hydrogen sulfide, with complications such as vomiting blood, and
resulted in the employee’s death.
  Based upon the above facts and medical
opinions, this employee’s death can be admitted as a result of occupational illness
according to Article 37 of the Industrial Accident Compensation Insurance Act.