Chemical Hazards

Question 0

Combatting chemical hazards e.g. Air pollution

Answer 0

Clean air act 1956, updated 1993
- legislation to prohibit burning of smoke-producing fuel in certain areas

London low emission zone (LEZ)

• in place from February 2008,
• targets larger, heavy, diesel powered vehicles
• aim to reduce their use and hence reduce PM10 and NOx

Question 1

Great London smog, 1952 health consequences

Answer 1

During the smog, mortality increased (estimated ~4000 excess deaths, recently revised to ~12000)

Bell & DAvis, EHP 2001

Question 2

Asbestos context and consequences

Answer 2

EU banned import, production, use of asbestos

Worldwide, only 60 countries have banned its use despite health complications

Estimate that 4000-5000 deaths in the UK are related to asbestos exposure

Question 3

Hartung and Rovida. 2009. Chemical regulators have overreached

Answer 3

REACH – Requires companies that produce or sell chemicals in the European Union to register toxicity data on the compounds and outline any new tests needed to clarify their biological effects, especially on reproduction and the development of offspring à Multigenerational rat studies can cost up to €2 million (US$2.8 million) per chemical

Positives
o It has forced companies to collate a great deal of existing information about the chemicals they handle, which is an improvement on the situation before REACH. It has also got companies to work together and share data

Problems
o It has resources to check only a fraction of all data submissions for accuracy and compliance à Only 5% of dossiers that do not propose tests are checked – a major limitation of REACH was the lack of resources.
o Generating data to comply with REACH will require 54m vertebrate animals and cost €9.5 billion over the next 10 years à20x more animals + 6x the costs of the official estimates. Most use for reproductive toxicity testing (90% animal use + 70% cost)
o Roughly one-third of the dossiers provide animal data on reproductive and developmental toxicity. But much of the information is from old studies
o Some 36% of the dossiers she looked at fail to make conclusive judgements about the chemical’s reproductive or developmental toxicity (see ‘Case study: Chloroaniline’) — but only 7% and 7.5%, respectively, propose new animal studies to clarify these effects.
o Only 2 studies proposed non-animal studies, and many companies were limited as few non-animal “scientifically acceptable or ready for regulatory use”. In contrast to encouragement for creative approaches to minimise animal testing.
o For around 21% of the dossiers studied by Rovida, reproductive toxicity was judged solely using read-across methods (the effects of a substance on human health are predicted by considering the effects of structurally similar chemicals). Although read-across may be appropriate for simple chemical and physical properties, toxicologists are far less positive about its validity for assessing reproductive and developmental toxicity, especially in the absence of other animal test data on the substance.
o The legislation does allow companies to suggest waiving reproductive and developmental toxicity tests, but only if people are unlikely to be significantly exposed to the substance, or if it is already known to damage DNA or gametes. But used quite broadly.

Solution
o Short Term – Urgent review of testing requirements for reproductive toxicity + Extended one-generation study instead of two-generation
o Medium-Term – Partnership similar to European Commission and cosmetic industry
o Longer-Term – Move into 21st century by moving to high-throughput methods using human cells, fish eggs, invertebrates, computational methods

Question 4

Chemical regulators have overreached
Nature 2009 editorial

Reach = registration, evaluation, authorisation and restrictions of chemicals 
Aim = improve consumer safety

Answer 4

• More than 100,00 synthetic chemicals are used in consumer products
• REACH aims to assess the toxicity of all chemicals and complete data collection by 2018
• Among factors that have increased consts and animal numbers are changes to the final legislation such as the inclusion of reaction intermediates and changes to the guidance for industry on how to test
• The chemical industry in Europe has grown by about 5% per year
• REACH will require 54 million animals and €9.5 billion over the next 10 years; 20 times more animals and 6 times more costs