What is mold?

Mold (or mould) is a term used to refer to fungi that grow in the form of multicellular thread-like structures called hyphae. Fungi that exist as single cells are called yeasts. Some molds and yeasts cause disease or food spoilage, others play an important role in biodegradation or in the production of various foods, beverages, antibiotics and enzymes.

Where does mold grow?

Mold is also found in damp building materials where it often appears like stains and comes in a variety of colours. A must smell is an indication of microbial growth even when there is no visible growth. If mold is allowed to grow in homes or offices it can contribute to poor indoor air quality. Some molds such as the Dry Rot Fungus, Serpula lacrymans, are highly destructive. For more details about dry rot fungus read Occurrence and Significance of Dry Rot Fungus, Serpula lacrymans.

Mold growth requires moisture. The sources of moisture could be Washing, cooking, air humidifiers, condensation or leaks from plumbing or from the outside. Poor ventilation contributes to higher humidity levels and leads to condensation, which also allows mold growth.

Molds release small “spores” into the air. So, when mold grows indoors, the number of mold spores and fragments is usually higher indoors than it is outdoors. These spores are small enough that people can actually inhale them deep into the lungs. Inhalation of spores poses risk of developing respiratory problems. With the exception of winter months mold spores are always present outdoors.

credit: Mold Bacteria Facts


What is asbestos?

Asbestos refers to a group of six types of naturally occurring minerals. Asbestos minerals are made up of fine, durable fibers and are resistant to heat, fire and many chemicals. Once called the “miracle mineral” for such properties, asbestos was used in a slew of everyday products, from building materials to fireproof protective gear. It is now widely known that exposure to asbestos can cause mesothelioma, a fatal cancer that affects the lining of the lungs, as well as other cancers and lung-related illnesses.

credit: Pleural Mesothelioma Center

What are the health effects of asbestos?

The human health effects from long-term unsafe asbestos exposure are well documented. Asbestos fibres are easily inhaled and carried into the lower regions of the lung where they can cause fibrotic lung disease (asbestosis) and changes in the lining of the chest cavity (pleura). These diseases can lead to reduced respiratory function and death. Long-term inhalation of asbestos fibres also increases the risk of lung cancer and mesothelioma.

Enlargement of the heart can also occur as an indirect effect from the increased resistance of blood flow through the lungs.

People are more likely to experience asbestos-related disorders if they:

  • are exposed to high concentrations of asbestos,
  • are exposed for longer periods of time, and/or
  • are exposed to asbestos more frequently.


What is Lead

Lead is a naturally occurring toxic metal found in the Earth’s crust. Its widespread use has resulted in extensive environmental contamination, human exposure and significant public health problems in many parts of the world.

credit: EPA

Where is Lead Found?

Lead can be found in all parts of our environment – the air, the soil, the water, and even inside our homes. Much of our exposure comes from human activities including the use of fossil fuels including past use of leaded gasoline, some types of industrial facilities, and past use of lead-based paint in homes. Lead and lead compounds have been used in a wide variety of products found in and around our homes, including paint, ceramics, pipes and plumbing materials, solders, gasoline, batteries, ammunition, and cosmetics.

Lead may enter the environment from these past and current uses. Lead can also be emitted into the environment from industrial sources and contaminated sites, such as former lead smelters. While natural levels of lead in soil range between 50 and 400 parts per million, mining, smelting, and refining activities have resulted in substantial increases in lead levels in the environment, especially near mining and smelting sites.

When lead is released to the air from industrial sources or vehicles, it may travel long distances before settling to the ground, where it usually sticks to soil particles. Lead may move from soil into ground water depending on the type of lead compound and the characteristics of the soil.

Federal and state regulatory standards have helped to reduce the amount of lead in air, drinking water, soil, consumer products, food, and occupational settings.

What are the Health Effects of Lead?

Lead can affect almost every organ and system in your body. Children six years old and younger are most susceptible to the effects of lead.


Even low levels of lead in the blood of children can result in:

  • Behavior and learning problems
  • Lower IQ and Hyperactivity
  • Slowed growth
  • Hearing Problems
  • Anemia

In rare cases, ingestion of lead can cause seizures, coma and even death.

Pregnant Women

Lead can accumulate in our bodies over time, where it is stored in bones along with calcium. During pregnancy, lead is released from bones as maternal calcium and is used to help form the bones of the fetus. This is particularly true if a woman does not have enough dietary calcium. Lead can also cross the placental barrier exposing the fetus the lead.  This can result in serious effects to the mother and her developing fetus, including:

  • Reduced growth of the fetus
  • Premature birth
Who is at Risk?


Lead is particularly dangerous to children because their growing bodies absorb more lead than adults do and their brains and nervous systems are more sensitive to the damaging effects of lead. Babies and young children can also be more highly exposed to lead because they often put their hands and other objects that can have lead from dust or soil on them into their mouths. Children may also be exposed to lead by eating and drinking food or water containing lead or from dishes or glasses that contain lead, inhaling lead dust from lead-based paint or lead-contaminated soil or from playing with toys with lead paint.

Adults, Including Pregnant Women

Adults may be exposed to lead by eating and drinking food or water containing lead or from dishes or glasses that contain lead. They may also breath lead dust by spending time in areas where lead-based paint is deteriorating, and during renovation or repair work that disturbs painted surfaces in older homes and buildings. Working in a job or engaging in hobbies where lead is used, such as making stained glass, can increase exposure as can certain folk remedies containing lead. A pregnant woman’s exposure to lead from these sources is of particular concern because it can result in exposure to her developing baby.

Lower Your Chances of Exposure to Lead

Simple steps like keeping your home clean and well-maintained will go a long way in preventing lead exposure. You can lower the chances of exposure to lead in your home, both now and in the future, by taking these steps: