Public health

Study and action concerning health at the population level. Prevention research evaluates benefits, harms, reach and distribution of outcomes as well as efficacy among those who receive an intervention.

Control and assessment of hazards that can make food harmful. Microbial contamination, chemical exposure and physical hazards require different measurements, connecting production and handling with effects on health.

Examination and assessment of meat and associated tissues for food-safety purposes. Observed lesions can guide decisions, but inspection criteria and sampling limitations determine which hazards it can detect.

Exclusion of the entire carcass from food use. This differs from condemnation of an isolated diseased organ; the nature and distribution of disease, and the applicable jurisdiction and date, matter.^[ref]

An international public-health institution within the United Nations system. Its scientific role includes coordination of surveillance, health evidence and international guidance; the institution’s identity is distinct from the conclusions of any one report.^[ref]

The study and control of environmental influences on human health. It connects measurements of air, water, food and other exposures with the pathways through which they affect people.

The physical area and volume allotted around a hospital bed. Floor area, air volume and ventilation rate are different quantities, so more space alone does not specify the rate at which contaminated air is removed.

Addition or substitution of materials in bread examined in historical food-safety investigations. Chemical and microscopic identification supplied evidence about composition, while judgments of harm depended on the material and amount present.^[ref]

Exchange of indoor and outdoor air through designed or incidental pathways. Flow can dilute an indoor contaminant, but its effectiveness depends on supply, removal and mixing rather than room volume alone.

Ventilation flow divided by the relevant room volume, commonly expressed per hour. It is an exchange-rate measure; incomplete mixing means the same nominal value need not produce identical contaminant removal everywhere.^[ref]

Ventilation of a hospital patient-care space. Air exchange, distribution and source control jointly affect airborne contamination, connecting a building system with infection-control questions.

Presence of airborne substances or particles at concentrations that can cause harmful effects. Exposure depends on composition, concentration and duration, so a single total quantity does not characterize every hazard.^[ref]

Suspended solid or liquid particles in air. Size affects transport, deposition and which fraction a measurement captures; equal particle mass can conceal different size distributions and compositions.

An airborne substance or particle capable of contributing to harmful environmental or health effects. Classification depends on the substance and exposure, rather than requiring visible smoke or a detectable odor.

Systems and practices that safely separate human waste from contact with people and the environment. It connects infrastructure and behavior with interruption of fecal contamination pathways.^[ref]

Reduction or inactivation of microorganisms on materials or in an environment to a specified purpose. It differs from removal of visible dirt and from sterilization, which addresses a more comprehensive microbial endpoint.

Use of heat to reduce viable microorganisms. Temperature, exposure time and the material’s thermal behavior affect the result, so a hot surface does not by itself establish the treatment achieved its intended endpoint.

Application of sewage to land; hydraulic suitability alone does not establish microbiological safety.

Wastewater containing domestic or other wastes, commonly including human excreta. Treatment separates and transforms contaminants before discharge or reuse, connecting waste handling with protection of water sources.

A historical excreta-management approach using dry Earth in receptacles, together with organized removal.

Removal of excreta and wastewater through drains and sewers using water as the carrying medium. Conveyance and safe final treatment are different requirements.

Assessment of the chemical, physical and biological properties of water in relation to its intended use.

The capacity of water to consume soap, chiefly because of dissolved calcium and magnesium ions. Quantitative results are commonly expressed as a calcium carbonate equivalent; this does not mean all the hardness originally existed as dissolved calcium carbonate.

A historical quantitative test in which a standardized soap solution is added to a measured water sample until a specified persistent lather appears. A reagent blank accounts for the amount needed to form the lather itself.

The historical operational fraction of Ammonia released by alkaline permanganate after preliminary removal of free Ammonia. It is neither a specific albumen measurement nor necessarily all organic nitrogen.

Investigation of a water supply and its surroundings to identify plausible contamination routes and failures of protective barriers.

Examination of water for specified microorganisms or microbial indicators using validated procedures. Chemical clarity alone cannot establish microbiological safety.

Water intended for human consumption.

The capacity of water to dissolve lead from materials it contacts; dissolved release should be distinguished from carriage of particles containing lead.^[ref]

Intervention intended to reduce new cases or relevant risks before the target disorder develops. A change in knowledge or symptoms is not automatically evidence of fewer first onsets; research must specify baseline diagnostic status and follow-up outcomes.

Prevention targeting people showing early signs or markers without currently meeting the relevant diagnostic threshold. A study enrolling both previously affected and never-affected participants should distinguish recurrence from first onset.

Prevention targeting a group with elevated risk because of shared characteristics or experiences, without requiring each recipient to show early symptoms. Parental bereavement is one example of a selection criterion, not itself a diagnosis.

A preventive program involving caregiver and youth groups after parental death, targeting parenting, coping and adjustment. Trials distinguish changes in symptoms and functioning from uniform prevention of every diagnosis.

Prevention offered to a whole specified population regardless of individually assessed risk. Universal delivery can produce different effects across subgroups and does not imply that every participant has equal risk.

A cognitive-behavioral prevention program studied in school and other settings. A trial with a nonspecific-program comparison found heterogeneous school results and no overall average depressive-symptom benefit in the full sample; program identity alone does not guarantee prevention of disorder.^[ref]

A classroom behavior-management approach using rules, teams and contingent rewards. Preventive field trials test whether changing early classroom behavior affects later outcomes; results depend on population, implementation and follow-up, not only on the program's name.

Study of the distribution and determinants of health-related outcomes in populations. Incidence, recurrence and prevalence answer different questions and should not be exchanged when evaluating prevention.

An epidemic extending over a large geographic area or across countries. The term describes distribution and does not by itself specify the risk or severity for one individual.

Study of the distribution, determinants and course of psychiatric outcomes in populations. Differences in symptom burden, first-onset incidence, recurrence and service-record diagnoses require different interpretations.

A researcher studying the distribution and determinants of psychiatric conditions in populations. Diagnostic definitions, sampling and ascertainment affect measured prevalence, connecting clinical classification with population-level inference.

A psychiatric epidemiologist who used an externally generated income change to investigate childhood psychiatric outcomes.^[ref]

A characteristic associated with lower risk or a weaker effect of a risk exposure under specified conditions. Causal protection requires stronger evidence than an unadjusted association.

A pattern in which a resource modifies the relationship between adversity and an adverse outcome. In the model $\mathbb{E}[D\mid S,P]={\beta }_0+{\beta }_{1}S+{\beta }_{2}P+{\beta }_{3}SP$, a negative ${\beta }_3$ attenuates the adversity slope as the resource increases. Its interpretation is scale dependent, and an observational interaction is not automatically a causal buffering effect.

A characteristic associated with increased probability of an outcome. Association can arise from causal influence, confounding or selection; being predictive does not automatically make a factor a modifiable causal target.

The difference between two outcome probabilities over specified populations and follow-up periods. With intervention risk $p_1$ and comparison risk $p_0$, a beneficial reduction in an adverse outcome has $RD<0$ and absolute risk reduction $p_0-p_1$. A causal interpretation requires a suitable design or identification assumptions; a simple difference between selected observational groups is not automatically a treatment effect.