In Flint, Michigan, a 2014 water-source switch was made without corrosion control. Which pathway carried lead to residents?

At Minamata, Japan, a chemical factory discharged methylmercury into the bay. How did residents receive the highest exposure?

During the Bhopal disaster, a pesticide plant released methyl isocyanate gas over nearby neighborhoods. What was the principal acute exposure pathway?

At Love Canal, leaking chemical drums were buried in a landfill near homes. Which transport pathway moved contaminants from the landfill toward residences?

In Woburn, Massachusetts, a childhood leukemia cluster was investigated for links to industrial solvents such as TCE. What exposure pathway was investigated?

During London's 1952 smog episode, smoke and sulfur dioxide accumulated near the ground. How were people primarily exposed?

In Bangladesh, millions of people were exposed for years to naturally occurring inorganic arsenic. What was the main route of chronic exposure?

After Chernobyl, radioactive iodine fell on pastures where dairy cows grazed. Which pathway could expose a child?

At Libby, Montana, vermiculite mining and processing released friable asbestos into the community. Which pathway posed the greatest concern?

After Flint's water-source switch, blood tests showed many children had raised levels of a neurotoxic agent that leached from old pipes. Which agent was it?

Residents near Minamata Bay developed severe neurological disease after eating local seafood. Which agent caused Minamata disease?

The Bhopal disaster caused acute respiratory and eye injuries after a pesticide-plant release. Which chemical agent was released?

Long-term use of contaminated tubewell water in Bangladesh can cause skin lesions and cancer. Which agent is responsible?

Which air-pollution agents were central to the respiratory health crisis during London's 1952 smog?

At Libby, Montana, miners and residents faced increased risks of lung disease and mesothelioma. Which agent caused this hazard?

Haiti's 2010 epidemic spread through contaminated river water and caused acute watery diarrhea and severe dehydration. Which pathogen caused it?

After Chernobyl, which radionuclide was especially important in the milk pathway because the thyroid takes it up?

In the Broad Street cholera outbreak, why did use of one pump spread disease through the neighborhood?

During Haiti's 2010 cholera outbreak, people using untreated river or canal water faced infection. What link made this a waterborne pathway?

In Milwaukee's 1993 cryptosporidiosis outbreak, more than 400,000 people became ill. How did most people become infected?

In New York City's 1999 West Nile outbreak, virus was found in people, birds, and mosquitoes. How did the vector connect birds to human cases?

During the Key West dengue outbreak of 2009-2010, why did eliminating breeding sites help interrupt transmission?

In Miami-Dade County's 2016 Zika outbreak, aerial insecticide spraying helped end local transmission. What pathway had the intervention interrupted?

At the 1976 Philadelphia Legionnaires' disease outbreak, people near the hotel became ill even if they had not entered it. Which pathway explains this pattern?

In Flint, adding corrosion control and replacing lead service lines addresses which part of the lead-exposure chain?

At Love Canal, officials capped the landfill and collected and treated leachate. What public-health problem did this response address?

John Snow persuaded officials to remove the Broad Street pump handle during the cholera outbreak. What did that response directly address?

During Haiti's 2010 cholera response, officials promoted chlorinated water, safe storage, sanitation, and handwashing. What did these measures target?

At Libby, Montana, cleanup removed contaminated vermiculite and dust from properties. What exposure route was this response designed to reduce?

In New York City's 1999 West Nile response, insecticide was applied to reduce adult mosquitoes. What component of the disease pathway did this address?