FABS 222 Module 4 Lecture 5: Chemical Water Quality

USASK/UOFS

MODULE 4 LECTURE 5: CHEMICAL WATER QUALITY

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Chemical hazards in food systems

Substances that can contaminate food or water and cause harm to human health, including pesticides, heavy metals, toxins, and industrial pollutants.

Natural chemical hazards

Toxic compounds naturally present in foods such as cyanogenic glycosides, mycotoxins, and plant alkaloids.

Synthetic chemical hazards

Human-made chemicals including pesticides, herbicides, industrial pollutants, and food additives used during production or processing.

Pesticide definition

Chemical substances used to control pests, weeds, fungi, or insects that damage crops.

Herbicides

Pesticides specifically used to kill unwanted plants or weeds competing with crops.

Insecticides

Chemicals used to kill insect pests that damage crops or transmit plant diseases.

Fungicides

Chemicals used to control fungal pathogens that cause plant diseases and spoilage.

Rodenticides

Chemicals used to control rodents that contaminate stored food.

Chemical residues

Small amounts of pesticides or chemicals remaining on food after application.

Maximum residue limit (MRL)

The highest level of pesticide residue legally allowed in food products.

Toxicity definition

The degree to which a substance can cause harm to living organisms.

Acute toxicity

Harmful effects that occur shortly after exposure to a chemical.

Chronic toxicity

Long-term health effects from repeated exposure to low levels of chemicals.

Dose-response relationship

Relationship between amount of exposure and severity of toxic effect.

LD50 definition

Dose required to kill 50% of test organisms; used to measure chemical toxicity.

Bioaccumulation

Build-up of chemicals in organisms over time.

Biomagnification

Increase in chemical concentration as it moves up the food chain.

Heavy metals

Toxic metals such as lead, mercury, cadmium, and arsenic that contaminate food and water.

Lead toxicity

Causes neurological damage and developmental problems.

Mercury toxicity

Affects nervous system and brain development.

Cadmium toxicity

Damages kidneys and weakens bones.

Arsenic contamination

Associated with cancer and chronic health effects.

Mycotoxins

Toxic chemicals produced by fungi contaminating crops.

Aflatoxin

Mycotoxin produced by Aspergillus species commonly found in peanuts and maize.

Mycotoxin health effects

Liver damage, cancer risk, and immune suppression.

Chemical contamination sources

Agriculture, industry, water pollution, and food processing.

Industrial pollutants

Chemicals released from factories that contaminate soil and water.

Persistent organic pollutants (POPs)

Chemicals that resist breakdown and remain in environment long-term.

Dioxins

Toxic environmental pollutants formed during industrial processes.

Polychlorinated biphenyls (PCBs)

Industrial chemicals that persist in environment and accumulate in fat.

Food additives

Chemicals intentionally added to improve shelf life, flavor, or texture.

Preservatives

Additives used to prevent microbial growth and extend shelf life.

Antioxidants

Additives that prevent oxidation and rancidity in foods.

Color additives

Chemicals used to improve or restore food appearance.

Flavor enhancers

Substances added to improve taste, such as MSG.

Food safety risk assessment

Scientific evaluation of chemical hazards and exposure levels.

Hazard identification

Determining whether a chemical can cause harm.

Exposure assessment

Estimating amount of chemical consumed.

Risk characterization

Combining hazard and exposure to estimate risk.

Chemical risk management

Policies and controls used to reduce exposure.

Acceptable daily intake (ADI)

Amount of chemical that can be consumed daily without health risk.

Regulatory agencies

Organizations that regulate chemical safety in food systems.

CFIA role

Canadian Food Inspection Agency monitors food safety and chemical contaminants.

PMRA role

Pest Management Regulatory Agency regulates pesticide use and safety.

Good agricultural practices

Proper pesticide use to minimize residues and contamination.