Final NEHA Exam Questions with All Correct Answers Updated.
INTRODUCTION
This comprehensive study guide features verified multiple-choice
questions covering the most frequently tested topics on the NEHA
Registered Environmental Health Specialist/Registered Sanitarian
(REHS/RS) credentialing examination, including environmental health
fundamentals, food protection, potable water, wastewater treatment,
solid and hazardous waste, vector control, radiation protection,
occupational safety, air quality, housing sanitation, and emergency
preparedness. Each question is paired with the correct answer in bold
italics and a detailed rationale explaining the underlying environmental
health principles and regulatory requirements. Based on the latest
2026/2027 examination standards and the NEHA 15-chapter Study Guide,
this resource is designed for environmental health professionals
preparing for the REHS/RS certification exam.
,SECTION 1: ENVIRONMENTAL HEALTH FUNDAMENTALS
Question 1
A factor or agent that increases the risk of developing cancer is referred
to as a:
A) Teratogen
B) Mutagen
C) Carcinogen
D) Fomite
Answer: C) Carcinogen
Explanation: Carcinogens are substances or agents that directly promote
the development of cancer by causing cellular mutations, disrupting
normal cellular growth regulation, or damaging DNA. Teratogens cause
birth defects, mutagens induce genetic mutations, and fomites are
inanimate objects that can transmit infectious agents .**
Question 2
An illness caused by a specific infectious agent or its toxic products,
transmitted from a reservoir to a susceptible host through direct or
indirect pathways, is classified as:
A) An infectious disease
B) A communicable disease
,C) A genetic disease
D) A noncommunicable disease
Answer: B) A communicable disease
Explanation: A communicable disease is specifically defined as an illness
resulting from an infectious agent that is transmitted from one host to
another, either directly through contact or indirectly through vectors,
vehicles, or environmental reservoirs. This distinguishes it from
infectious diseases that may not be transmissible between hosts .**
Question 3
The leading causes of mortality across all age groups in the United States
include all of the following EXCEPT:
A) Heart disease
B) Malignant neoplasms
C) Homicide
D) Chronic lower respiratory diseases
Answer: C) Homicide
Explanation: The four major causes of death in the United States are
heart disease, cancer, chronic lower respiratory diseases, and accidents.
Homicide, while a significant public health concern, does not rank among
the top four causes of mortality across all age groups .**
, Question 4
An action authorized by law to restrict or prevent the movement of goods
for the protection of public health, safety and welfare is called:
A) An injunction
B) An embargo
C) An order to cease and desist
D) A subpoena
Answer: B) An embargo
Explanation: An embargo is a legal action authorized to restrict or
prevent the movement of goods for the protection of public health, safety,
and welfare. This is a critical enforcement tool used by environmental
health professionals .**
Question 5
Field observations are not always reported in total because:
A) The reported forms are usually inadequate
B) The significance of the data is not understood
C) The field staff are too busy
D) The data is confidential
Answer: A) The reported forms are usually inadequate
INTRODUCTION
This comprehensive study guide features verified multiple-choice
questions covering the most frequently tested topics on the NEHA
Registered Environmental Health Specialist/Registered Sanitarian
(REHS/RS) credentialing examination, including environmental health
fundamentals, food protection, potable water, wastewater treatment,
solid and hazardous waste, vector control, radiation protection,
occupational safety, air quality, housing sanitation, and emergency
preparedness. Each question is paired with the correct answer in bold
italics and a detailed rationale explaining the underlying environmental
health principles and regulatory requirements. Based on the latest
2026/2027 examination standards and the NEHA 15-chapter Study Guide,
this resource is designed for environmental health professionals
preparing for the REHS/RS certification exam.
,SECTION 1: ENVIRONMENTAL HEALTH FUNDAMENTALS
Question 1
A factor or agent that increases the risk of developing cancer is referred
to as a:
A) Teratogen
B) Mutagen
C) Carcinogen
D) Fomite
Answer: C) Carcinogen
Explanation: Carcinogens are substances or agents that directly promote
the development of cancer by causing cellular mutations, disrupting
normal cellular growth regulation, or damaging DNA. Teratogens cause
birth defects, mutagens induce genetic mutations, and fomites are
inanimate objects that can transmit infectious agents .**
Question 2
An illness caused by a specific infectious agent or its toxic products,
transmitted from a reservoir to a susceptible host through direct or
indirect pathways, is classified as:
A) An infectious disease
B) A communicable disease
,C) A genetic disease
D) A noncommunicable disease
Answer: B) A communicable disease
Explanation: A communicable disease is specifically defined as an illness
resulting from an infectious agent that is transmitted from one host to
another, either directly through contact or indirectly through vectors,
vehicles, or environmental reservoirs. This distinguishes it from
infectious diseases that may not be transmissible between hosts .**
Question 3
The leading causes of mortality across all age groups in the United States
include all of the following EXCEPT:
A) Heart disease
B) Malignant neoplasms
C) Homicide
D) Chronic lower respiratory diseases
Answer: C) Homicide
Explanation: The four major causes of death in the United States are
heart disease, cancer, chronic lower respiratory diseases, and accidents.
Homicide, while a significant public health concern, does not rank among
the top four causes of mortality across all age groups .**
, Question 4
An action authorized by law to restrict or prevent the movement of goods
for the protection of public health, safety and welfare is called:
A) An injunction
B) An embargo
C) An order to cease and desist
D) A subpoena
Answer: B) An embargo
Explanation: An embargo is a legal action authorized to restrict or
prevent the movement of goods for the protection of public health, safety,
and welfare. This is a critical enforcement tool used by environmental
health professionals .**
Question 5
Field observations are not always reported in total because:
A) The reported forms are usually inadequate
B) The significance of the data is not understood
C) The field staff are too busy
D) The data is confidential
Answer: A) The reported forms are usually inadequate
