guideline derivation std setting II dec 15 compatibility mode

Environmental guidelines/standardsDr Leonard Ritter University of Guelph Environmental guidelines/standards Dr Leonard Ritter University of Guelph Dr Kersten Gutschmidt World Health Orga

Environmental guidelines/standards

Dr Leonard Ritter

University of Guelph

Environmental guidelines/standards

Dr Leonard Ritter

University of Guelph

Dr Kersten Gutschmidt

World Health Organization

Protection of the Human Environment (PHE)

International Programme on Chemical Safety (IPCS)

Content

guideline versus standard WHO Air Quality Guidelines WHO Guidelines for Drinking Water Quality Codex Alimentarius Food Standards

Reliance

on cars

Pressures

Driving

forces

Dependency on chemicals to improve

quality of life; consumption patterns

Toxic emissions; waste generation; water

use, energy use

Environmental health cause

Environmental health cause effect framework: Factors and action related to effect framework: Factors and action related to

chemicals use

- promote changes of consumption

- implement an integrated product policy.

- set emission limits;

- establish safety procedures;

- prevent accidents.

- set environmental quality and

Action Factor

^

Action

Exposure

State

Effect

Chemicals in the environment, food, and

products; urban air quality; climate change

Exposure, intake, and dose of workers

and the public

Morbidity, mortality, and accidents in

workers and general public; poisonings

set environmental quality and food standards.

- classify and label chemicals ;

- evaluate uses and decide on use restrictions;

- establish product registers.

- establish Poisons Centres;

- keep stocks of antidotes;

- prepare for responding to accidents.

Guidelines:

recommendations recommendations scientific scientific

health (risk) based health (risk) based guidance to govern guidance to

govern Guidelines versus standards

ments for standard setting Standards:

limit values fixed in law limit values fixed in law considers socio considers socio economic factors

Guideline values:

Guideline values: threshold substances threshold substances

• Evaluate information on toxicity

• Describe dose-response relationship

– e.g NOAEL or LOAEL for the critical effect in

the most relevant study

• Apply an uncertainty factor

• Derive at a tolerable intake (TI)Derive at a tolerable intake (TI)

• Estimate exposure route proportions of TI

• Allocate proportions of TI to media of exposure

Ó GVs not necessarily represent national or local

exposure situations

Ó GVs should be adapted to local circumstances

Guideline values,

Guideline values, example: chlorinated hydrocarbons (1) example: chlorinated hydrocarbons (1)

(according to EHC 170)

•• media concentration media concentration – ambient air: < 0.10 μg/m3(indoor air levels are similar)

– drinking-water: 0.003 μg/L to < 0.02 μg/L.

– food: 0.0018 μg/g (detected only in meat)

– soil: no data.

– consumer products: no data

•• estimates of exposure in estimates of exposure in μμg/kg body weight (bw) per day g/kg body weight (bw) per day.

Ðambient air 0.034 (bw: 64 kg; breathing: 22 m3/day)

Ðdrinking-water 0.0007 - < 0.0004(1.4 L water/day)

Guideline values,

Guideline values, example: chlorinated hydrocarbons (2) example: chlorinated hydrocarbons (2)

(according to EHC 170)

Ðdrinking water 0.0007 0.0004 (1.4 L water/day)

Ðfood 0.004 (125 g meat composite/day)

ÐTotal intake 0.03 μg/kg bw per day.

•• relative media contribution to total exposure relative media contribution to total exposure – outdoor/indoor air: < 0.03 = 85.92% (86%).

– drinking-water: 0.000235 = 0.78% (0.8%).

Guideline values,

Guideline values, example: chlorinated hydrocarbons (3) example: chlorinated hydrocarbons (3)

(according to EHC 170)

– food: 0.004 = 13.3 % (13%)

– soil: no data.

– consumer products: no data.

•• NOAEL NOAEL

– available data on inhalation studies are inadequate.

– data shows that inhalation is the main exposure route for

adults, however, the principal route of intake of the most

exposed group (breast fed infants) is ingestion (of mothers

milk).

Guideline values,

Guideline values, example: chlorinated hydrocarbons (4) example: chlorinated hydrocarbons (4)

(according to EHC 170)

– NOAEL is 60 mg/kg bw per day from a long term ingestion

study with renal tubular degeneration observed at higher

doses; 5 days per week feeding study; rat.

Guideline values:

Guideline values: non non threshold substances threshold substances

• Evaluate information on toxicity

• Describe dose-response relationship

– e.g low-dose extrapolation (e.g linear extrapolation)

• Derive at a risk estimate

– e.g unit risks: cancer risk estimate for lifetime exposure to a concentration of lifetime exposure to a concentration of e.g 1 μg/m3(e.g WHO AQG);

– exposure associated with risks to develop the disease in question such as

10-3, 10-4(e.g WHO Drinking Water Guidelines)

Ó no GVs for non-threshold substances by WHO

Organic air pollutants:

Acrylonitrile, Benzene, Carbon disulfide, 1,2-Dichloroethane, Dichloromethane, Formaldehyde, Polynuclear aromatic hydrocarbons (carcinogenic fraction), Styrene, Tetrachloroethylene, Tolouene, Trichloroethylene, Vinyl chloride

Inorganic air pollutants:

Arsenic, Asbestos, Cadmium, Carbon monoxide, Chromium, Hydrogen sulfide, Lead, Manganese, Mercury, Nickel, Nitrogen oxides,

Ozone/photochemical oxidants, Particulate matter, Radon, Sulfur oxides, Vanadium extrapolation)

WHO Air Quality Guideline: criteria for inclusion of substances

• sources, levels, and routes of exposure.

• kinetics and metabolism

• LOAELs and/or NOAELs for humans, animals,

and plants.

• Uncertainty factors.

IARC l ifi ti f i

• IARC classification of carcinogens.

• Quantitative assessment of carcinogenic

potency from animal studies.

• Unit lifetime risk from human epidemiological

data.

• Ecological effects

WHO Air Quality Guideline: Classical Air Pollutants

Compound Guideline value Guideline value Averaging time

60 mg/m3 30 min

30 mg/m3 1 h

10 mg/m3 8 h

NO2 2 200 μg/mμg 3 1h

40-50 μg/m3 annual

125 μg/m3 24 h

50 μg/m3 annual Particles no GV (dose-response curve)

0.5 to 1.0 μg/m3 annual

Comparison of WHO Air Quality Guidelines with national

ambient air quality standards:

Country 1 hr 24 hrs Annual 1 hr 24 hrs Annual 1 hr 8 hrs 1 hr 8 hrs 24 hrs annual 24 hrs Annual

-Australia 0.44 0.16 - 0.30 0.12 - 34.3 11.4 0.24 0.10 - - -

Australia 0.44 0.16 0.30 0.12 34.3 11.4 0.24 0.10

-Thailand 0.78 0.30 0.14 0.32 - - 34.2 10.3 0.20 - 0.33 0.10 0.12 0.05

Drinking

Drinking water water

An established goal of WHO and its Member states

is that:

all people, whatever their stage of

development and their social and economic

development and their social and economic

conditions, have the right to have access to

an adequate supply of safe drinking-water.

What does ‘safe’ mean in this context?

‘Safe’ refers to a water supply that is:

• of a quality which does not represent a significant health risk;

• is of sufficient quantity to meet the domestic needs;

• is available continuously,

• is available to all the population; and

• is affordable.

WHO Guidelines for Drinking WHO Guidelines for Drinking Water Quality Water Quality

Volume 1- recommendations:

• criteria used in selecting microbiological, chemical and radiological contaminants

• approaches used to derive the GVs

• brief information supporting GVs recommended or why

no GV has been given

Volume 2 - health criteria and other supporting information:

• Elaborates greatly on the health risk assessment of microbial and chemical contaminants presented in Volume 1

Volume 3 - Surveillance and control of community supplies:

• deals specifically with small communities in developing countries

Guideline value for chemicals

• Represents the concentration of a chemical constituent that

does not result in any significant risk to health of the

consumer over a lifetime of consumption

• Short-term deviations above the guideline values does not

necessarily mean that the water is of unsuitable

consumption

• GVs should not be regarded as implying the quality of

drinking water may be degraded

• When a GV is exceeded, the authority responsible for public

health should be consulted for suitable action

• When developing national standards based on the GVs, it

will be necessary to take into account geographical,

socio-economic, dietary and other conditions affecting potential

exposure

Guideline value for chemicals (cont’d)

•• GVs must be practical and feasible to implement

– GVs are not lower than limit of detection under routine laboratory operating conditions

– GVs are recommended only when control techniques are available to remove or reduce contaminants to the desired level

•• No GVs for the aesthetic acceptability of the water.

•• Some of the agents evaluated are essential for life No attempt was made to define minimum desirable concentrations.

•• GVs are set at a level to protect human health; they may not be suitable for the protection of aquatic life.

•• GVs apply to bottled water and ice but do not apply for mineral waters, which are regarded as beverage

WHO Guidelines for Drinking

WHO Guidelines for Drinking Water Quality Water Quality

• acute problems are rare

• chronic/cumulative problems are more common

• GV in concentrations in mg/litre for:

– inorganic substances – organic substances – pesticides – disinfectant and disinfectant by-products

WHO Guidelines for Drinking WHO Guidelines for Drinking Water Quality: Water Quality:

derivation of GVs: threshold substances

• review of scientific database

• estimation of tolerable daily intake (TDI) for exposure from all sources

• adjustment to body weight

• adjustment for daily drinking-water consumption

• allocation of percentage of TDI (default value is 10%) to drinking water intake

WHO Guidelines for Drinking

WHO Guidelines for Drinking Water Quality: Water Quality:

derivation of GVs: non

derivation of GVs: non threshold substances threshold substances

• 60 kg adult drinking 2 litres of water per day for

70 years

• use of linearized multistage model

• calculation of drinking water concentrations associated with an excess cancer risk of:

4

– 10-4(additional cancer cases per 10 000 of the population)

– 10-5(additional cancer cases per 100 000 of the population)

– 10-6(additional cancer cases per 1 000 000

of the population)

Ð WHO does not define “acceptable risk” This is

a national, societal matter

WHO Guidelines for Drinking WHO Guidelines for Drinking Water Quality: Water Quality:

provisional guideline values

A provisional guideline value is recommended where:

• there is evidence of a potential hazard but data is limited and the UF is larger than 1000

• the calculated GV is below the analytical y quantification limit

• the calculated GV is below the level that can be achieved by water treatment

• the calculated guideline will be exceeded

as a result of water disinfection

• for carcinogens where a guideline value equivalent to 10-5lifetime excess cancer risk is not feasible

FOOD

The Codex Alimentarius Commission

The Codex Alimentarius Commission was created in

1963 by FAO and WHO to develop food standards,

guidelines and related texts such as codes of practice

under the Joint FAO/WHO Food Standards Programme.

Codex Alimentarius Commission

Main objectives are:

• to protect the health of consumers and ensuring fair practices in food trade;

• to promote coordination of food standards work undertaken by IGOs and NGOs.

• to determine priorities initiate and guide the

• to determine priorities, initiate and guide the preparation of draft standards;

• to finalize standards and, after acceptance by governments, publish them.

• to amend published standards, after appropriate survey in the light of developments

Subsidiary bodies of the Codex Alimentarius Commission

‡ Coordinating Committees

– (sub) regions coordinate food standards activities, including the

development of regional standards

‡ Codex Committees

– prepare draft standards for submission to the Codex Alimentarius

Commission

Commodity Committees

– Commodity Committees

• responsible for developing standards for specific foods or food

classes (‘vertical committees’)

– General Subject Committees

• are so called because their work has relevance for all Commodity

Committees, since this work applies across the board to all

commodity standards (‘horizontal committees’)

Codex General Subject Committees

Food Additives and Contaminants

Pesticide Residues

Residues of Veterinary Drugs

Others, including General Principles

Codex general subject committees

and Contaminants (CCFAC)

Residues (CCPR)

Veterinary Drugs

in Foods (CCRVDF)

General Principles, Food Labelling, &

Food Hygiene

Among other things, Codex Committees review draft standards provided based on advice of independent scientific expert bodies to be submitted to the Codex Alimentarius Commission

Risk analysis

• Risk assessment – primarily the responsibility of

scientific committees

• Risk management – primarily the responsibility of

Codex committees

• Risk communication – between risk assessors and

managers, and with the public

• Established in 1955, JECFA considers mainly chemical and toxicological aspects of additives, contaminants and residues of veterinary drugs in food

• JECFA members are experts appointed in their own right and not as government representatives

• JECFA is independent from the Codex Alimentarius Commission

Joint FAO/WHO Expert Committee on Food Additives (JECFA)

Commission

• CCFAC and CCRVDF identify food additives, contaminants and veterinary drug residues that should receive priority evaluation and refer them to JECFA

• Reports of toxicological evaluations are published

• JECFA also provides scientific advice directly to FAO and WHO Member States

• Established in 1955, JECFA considers chemical,

toxicological and other aspects of contaminants and

residues of veterinary drugs in food

• JECFA members are experts appointed in their own right

and not as government representatives

Joint FAO/WHO Expert Committee on Food Additives (JECFA)

• Scientific evaluation of:

– chemical additives in food – residues of veterinary drugs in food – food contaminants

• JECFA establishes Acceptable Daily Intakes (ADIs)

• JECFA recommends MRLs for veterinary drugs

• NOAEL divided by uncertainty factor

• most appropriate study; most sensitive species

• mg/kg of human body weight that can be ingested daily over a lifetime without appreciable health risk

Ð The ADI is used by Codex Alimentarius to set

Joint FAO/WHO Expert Committee on Food Additives (JECFA)

y permissible levels in food

by JECFA

• Established in 1963, JMPR should recommend maximum residue

limits (MRLs) for pesticides in food as well as methods of

sampling and analysis

• JMPR members are experts appointed in their own right and not

as government representatives

• JMPR is independent from the Codex Alimentarius Commission

Joint FAO/WHO Meeting on Pesticide Residues (JMPR)

• FAO appointees draft MRLs

• WHO appointees conduct toxicological evaluations

• Reports and evaluations are published

• CCPR identifies those pesticides requiring priority evaluation

After JMPR evaluation, CCPR discusses recommended MRLs

and, if acceptable forward them to the Codex Alimentarius

Commission for adoption as Codex MRLs

Scientific committees

• Provide recommendations that serve as the basis for Codex standards

• Administered by the World Health Organization (WHO), headquartered in Geneva, and the Food and Agriculture Organization of the United g g Nations (FAO), headquartered in Rome

• Composed of scientists who are invited on the basis of their scientific expertise

WHO participants

• Experts employed by universities and governments

• Evaluate toxicological and related data

• Establish “acceptable” or “tolerable” intakes for

the chemicals being evaluated, expressed as a g , p

“dose” in terms of mg (or μg)/kg body weight per

day

Committee relationships

• JECFA advises CCFAC on food additives and contaminants and CCRVDF on residues of veterinary drugs

• JMPR advises CCPR on pesticide residues

CCRVDF – Codex Committee on Residues of Veterinary Drugs in Foods