The Environmental Case Management of Lead-exposed Persons
Guidelines for
Public Health Units
Revised 2012
These guidelines are dedicated to John Feltham
CEng MICE MIMechE MIPENZ RegEng
(1931–1997) who made such a significant contribution
to improving environmental health in New Zealand.
Citation: Ministry of Health. 2012. The Environmental Case Management of Lead-exposed Persons: Guidelines for Public Health Units: Revised 2012. Wellington: Ministry of Health.
Published in February 2012 by the
Ministry of Health
PO Box 5013, Wellington 6145, New Zealand
ISBN 978-0-478-37395-0 (online)
HP 5455
This document is available at www.health.govt.nz
Preface
There is an increasing awareness about the hazards associated with lead and the risks, particularly to children, created by exposure to lead from various sources where young children gather and play. Exposure can occur in early childhood centres and playgrounds, but it is especially likely from lead-based paint in the home.
Families in older homes are at risk when lead-based paint is being removed or when it deteriorates (becomes flaky or powdery) and falls off. Soil and dust contaminated with lead in this way become pathways of exposure. There have been cases of children being fatally poisoned as a result of chewing or swallowing lead-based paintwork. Young children are most at risk because of their habit of placing things in their mouths, ingestion of non-food substances (pica), and greater absorption of the lead they take in than older children and adults. Adults may also be at risk from non-occupational exposures due to paint removal, smoking, hobbies and cleaning.
Lead absorption from other than occupational sources is a condition which is notifiable to the Medical Officer of Health under the Health Act 1956. The levels of blood lead which are required to be notified in New Zealand are ‘lead absorption equal to or in excess of 0.48 µmol/l’ (10µg/dl).
Actual notifications of raised blood lead levels are relatively frequent, but notification is not an accurate reflection of the problem. Many cases go undetected. The EpiSurv data showed that for the years 2001 to 2010 there were a total of 1468 notifications for the whole of New Zealand. This represents an average of about 143 notifications per year (LLopez, ESR Kenepuru Science Centre, personal communication, 6 April 2011).
These guidelines are intended to be a resource document for public health units who will be involved in the investigation and management of people who have been exposed to lead (not necessarily ‘lead poisoned’ in terms of the Health Act notification requirements).
While the guidelines are applicable for any age, there is an emphasis on measures for managing cases of lead-exposed children. Originally published in 1998 after field testing of interim guidelines for a year and redrafting, these guidelines have been updated to take account of recent developments in New Zealand and internationally with respect to management of lead exposure.
The revisions made to the 2007 edition focused on lead in soil, the Department of Labour notification blood lead level, and indoor shooting. The revisions highlighted the new Resource Management (National Environmental Standard for Assessing and Managing Contaminants in Soil to Protect Human Health) Regulations 2011, which came into effect in January 2012. Two appendices (7 and 8) have been added in relation to indoor shooting.
Acknowledgements
The 1998 guidelines were developed by John Feltham from work undertaken by the Public Health Service of Hutt Valley Health.
The Ministry of Health also gratefully acknowledges the contributions of Andrew Bichan (Hutt Valley Health), Kevin Campbell (Southern Public Health Services), Simon Church (Southern Public Health Services), Alan Freshwater (Auckland Healthcare), Bill Littley (Hawkes Bay Healthcare), Lyall Mortimer (Department of Labour Occupational Safety and Health), Brian Prendergast (Crown Public Health), Bruce Taylor and Professor Alistair Woodward in the development of the 1998 guidelines.
Contents
Introduction 1
Background 1
Purpose of the guidelines 1
Exclusions 2
Risk analysis 2
Further information 3
Chapter 1: Hazard Identification 4
Main points 4
Lead in paint 5
Lead in house dust 7
Lead in soil 11
Lead in water 14
Chapter 2: Dose Response, Exposure Assessment, Risk Characterisation and Risk Communication 16
Main points 16
Health effects 16
Exposure assessment 19
Risk characterisation 22
Risk communication 23
Chapter 3: Risk Management 25
Main points 25
Summary of the graded response protocol 25
Risk management 27
Graded response protocol 28
Chapter 4: Risk Management – Abatement 37
Main points 37
Introduction 38
Essential repairs 41
Paint film stabilisation 42
Surface coating 44
Treatment of friction and impact services 48
Paint removal 50
Enclosure 54
Building component replacement 57
Soil cover 59
Water 61
Protection during abatement 62
Clearance testing, ongoing monitoring and reevaluation 65
Chapter 5: Risk Management – Behaviour Modification 67
Main points 67
Introduction 67
House cleaning 68
Hygiene 70
Diet 72
Compliance monitoring and outcome evaluation 73
Chapter 6: Roles and Responsibilities 75
Role of public health units 75
Role of territorial authorities 76
Role of property owners 79
Role of property occupiers 80
References 81
Appendices
Appendix 1: Lead Sampling and Analysis 85
Appendix 2: Sample Letters for Paediatricians and Medical Practitioners 93
Appendix 3: Summary of Standards and Background Values for Lead in the Environment 95
Appendix 4: Principles of Behavioural Modification 96
Appendix 5: Food and Nutrition Guidelines 97
Appendix 6: Consumer Information Sources 100
Appendix 7: Report Sheets 101
Appendix 8: Health Advice for Indoor Shooters 117
Appendix 9: Minimising Lead Exposure in Shooting Club Ranges 121
Glossary 126
The Environmental Case Management of Lead-exposed Persons 129
Introduction
Background
These guidelines provide practical advice for the investigation and environmental case management of lead-exposed cases. They are intended to assist the public health team in achieving a tolerable level of lead in the environment for exposed children or adults, so limiting any adverse effect on their health. Making their environment ‘lead safe’ will also protect people who might otherwise be exposed to the same lead hazards in the future. Although the guidelines focus on secondary prevention, increasing evidence of the toxicity of lead at levels previously regarded as harmless strengthens the importance of primary prevention (CDC 2005).
The current average blood lead levels of children are in the range of 2–4 µg/dl
(0.1–0.2 µmol/l) in the United States and developed countries (Koller et al 2004). In the United States the adult average blood lead level is 1–2 µg/dl (Anon 2007). Although levels have reduced considerably in the last 30 years with the removal of lead from paint and petrol, they remain higher than in the pre-industrial era.
Purpose of the guidelines
The guidelines provide guidance to public health units that contribute to the management of risks to health from exposure to lead in non-occupational settings. People may be exposed to lead in non-occupational settings, primarily in and around the home.
Properly applied, the guidelines will assist with determining:
· the risk of a lead hazard
· appropriate advice on managing the risk, including risk communication.
The guidelines will normally be used in the context of ‘secondary prevention’ when a person is, or is suspected to be, exposed to lead. The guidelines are not intended for primary prevention of hazards arising from lead (eg, inspection, risk assessment and risk reduction from lead in dwellings regardless of a resident’s blood lead levels), although many of the basic procedures, sampling and abatement methods would be similar.
While lead-based paint hazards will frequently be implicated, the investigation of lead-exposed people should evaluate the contribution of all potential sources and media to cumulative lead exposure. Sources other than lead-based paint include lead transported home on work clothes, hobbies involving lead (eg, lead lighting, graphic materials, indoor rifle shooting), lead-based cosmetics and traditional medicines, leaded pottery and ceramic glazes, and lead in food and drinking-water.
Accordingly, this protocol assists public health units in identifying all contributory lead hazards and (open) exposure pathways using a combination of interview, visual observation, and laboratory testing. A management plan, typically incorporating both behavioural (educational) and environmental (abatement) strategies, can then be developed in consultation with the family. It must be emphasised that the guidelines aim to provide a ‘lead-safe’ environment; this is not the same as a lead-free environment.
Exclusions
These guidelines exclude places of work because these are covered by the Health and Safety in Employment Act 1992. The Department of Labour (Workplace Services) is responsible for enforcing the Health and Safety in Employment Act 1992. The home, public buildings and schools may be places of work if contractors are doing work in them.
Ambient (outside) air is covered by the Resource Management Act 1991. The Ministry for the Environment administers the Act, and the Act is implemented by regional councils in so far as it relates to the discharge of contaminants to air. Lead may also occur in ambient air from diffuse sources of exposure, but such sources are not considered within the scope of these guidelines. For example, prior to the removal of lead from petrol, vehicle emissions were a significant source of lead in the environment. Ambient air inside dwellings and point source release of lead around dwellings would, however, be covered by these guidelines.
Risk analysis
A public health risk analysis model is outlined in A Guide to Health Impact Assessment and forms the basis for these guidelines (Ministry of Health 1998). There are three sequential steps in the process of decision-making regarding risk:
1. Risk assessment
2. Risk communication
3. Risk management.
Risk assessment asks the following questions: ‘What are the risks?’ and ‘Who will be affected, how, and to what extent?’. It includes hazard identification, dose-response assessments, exposure assessment, and risk characterisation.
As the first step in the risk assessment process, hazards have to be identified. If the assessment of the hazard suggests the likelihood of significant risk is small, or control is straightforward and safe, it may not be necessary to proceed to the quantification of risk.
The next steps in risk assessment are the consideration of dose-response and the assessment of exposure to lead. Dose-response models are developed from epidemiological data. Lead exposures are determined through blood lead levels and exposure to lead sources. The information from these three steps is used in the final step of risk assessment: risk characterisation.
The acceptability of risk is a decision for either individuals, or society as a whole. Without societal judgements about acceptable risk no decisions can be reached on proposals that carry both benefits and risks. On the other hand, individuals expect to suffer no more than negligible harm unless they are taking voluntary risks in the pursuit of some activity in which they see benefits. Various scientific and regulatory bodies have set levels of what they consider to be acceptable risks, but there is no certainty that these levels will be understood or accepted by individuals.
During any communication of risk, there must be adequate consultation on the risks, and public concerns must be taken into account. Risk management seeks to address the following questions: ‘How can risks be avoided or reduced?’, ‘What are the options?’, ‘Are contingency and emergency plans adequate?’, ‘How can differing perceptions of risk be mediated?’ and ‘Can future health risks be predicted?’.
Further information
Much of the information in the guidelines has been drawn from the publications referred to in the references, in particular: Guidelines for the Evaluation and Control of Lead-Based Paint Hazards in Housing (Jacobs 1995) and Guidelines for the Management of Lead-Based Paint (Ministry of Health and Department of Labour 2008).
Chapter 1:Hazard identification
Main points
· Lead-based paint is almost certain to be present on pre-1945 paintwork and is likely to be present on pre-1980 paintwork.
· The US Environmental Protection Agency’s (US EPA) Final Rule (2001) clearance standards may be used as a guide to ‘safe’ dust lead loadings:
– floors (including carpeted floors) <430 µg/m2
– interior window sills <2700 µg/m2
– exterior surfaces <4300 µg/m2
· Lead contamination of soil around residential properties occurs mainly as a result of deterioration, damage or removal of exterior lead-based paintwork.
· There is evidence to suggest that soil removal and replacement may not be worthwhile as an abatement strategy at soil lead levels less than 3000 µg/g, but a more stringent standard, 210 µg/g, is likely to be appropriate for sandpit sand or other high-contact areas for young children.
· The contribution of soil lead to total cumulative lead exposure is highly variable, depending on such things as the content and bioavailability of lead in the soil and the behaviour of people in the household, particularly children.
· The soil contaminant standard to protect human health (SCS) of 210 µg/g is based on being routinely exposed to bare soil and includes exposure from consumption of home-grown produce.
· The SCS of 210 µg/g is more appropriate to be called the ‘level of concern’ for a residential setting and is recommended as a trigger for investigation (but not necessarily remediation). Note that the NES regulations use the SCS as a trigger for resource consent requirements.
· Lead levels for generic exposure scenarios – NES soil contaminant standards, µg/g:
– Rural residential/lifestyle block 25% produce 160
– Residential 10% produce 210
– High-density residential 500
– Recreational 880
– Commercial/industrial outdoor worker/maintenance 3300
Lead in paint
Introduction
Lead has been used in paint since ancient times, as a pigment and as a drying agent in oil-based paints. The concentration of lead in domestic paints declined dramatically over the latter half of the last century. It may be assumed that pre-1945 interior or exterior domestic paintwork contains a high lead content; pre-1965 paintwork probably does, while pre-1980 paintwork possibly does. Post-1980 paintwork may generally be assumed to have a very low lead content, unless old stock or industrial specification paint was used (inappropriately).
The list below shows key dates and events in the use of lead in paint in New Zealand.
· Before 1945, white lead (lead carbonate) was extensively used as a pigment in paint, especially exterior house paint (which contained up to 50 percent lead by weight in the dry film) and as a masonry filler mixed with gold-size. After the war, white lead was progressively replaced by titanium dioxide in domestic paint.