Model for Economic Assessment of Acid Damage to Building Materials

28 Model for Economic Assessment of Acid Damage to Building Materials Downloaded by UNIV OF CALIFORNIA SANTA BARBARA on March 2, 2018 | https://pubs.acs.org Publication Date: September 25, 1986 | doi: 10.1021/bk-1986-0318.ch028

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Thomas J. Lareau , Robert L. Horst, Jr. , Ernest H. Manuel, Jr. , and Frederick W. Lipfert 3,4

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U.S. Environmental Protection Agency, Washington, DC 20460 Mathtech Inc., 210 Carnegie Center, Princeton, NJ 08540 Brookhaven National Laboratory, Upton, NY 11973

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Using a "damage function" approach, material damages to building components associated with SO and wet acidic deposition are estimated for four case-study cities. The damage function method links the physical change (corrosion or erosion) associated with changes in pollutant levels with material inventory and economic data. The valuation of damages in monetary units is based on the increased maintenance and replacement costs associated with the reduced lifetimes of material components, e.g. painted exterior walls. The damage estimates are better than those heretofore available, given improvements in the quality and resolution of the material inventory and air quality data that have been developed as part of the National Acid Precipitation Assessment Program. 2

A i r p o l l u t i o n sources i n the United States and Canada c u r r e n t l y emit more than 25 m i l l i o n tons of s u l f u r d i o x i d e each year. S 0 and wet a c i d i c d e p o s i t i o n a r e b e l i e v e d t o cause damage t o a q u a t i c l i f e , crops, f o r e s t s , and m a t e r i a l s . The e f f e c t s on m a t e r i a l s i n c l u d e damages t o common construction materials including galvanized steel (zinc), paint, copper, b u i l d i n g stones and mortar, as w e l l as damages t o c u l t u r a l or h i s t o r i c objects and buildings. The response of both manufacturers and households t o p o l l u t a n t induced damage i s t o increase maintenance and t o f i n d ways t o c i r cumvent the d e t e r i o r a t i o n of materials through development of more r e s i s t a n t m a t e r i a l s and the use of s u b s t i t u t e s . The economic c o s t a s s o c i a t e d w i t h these a c t i v i t i e s i s p o t e n t i a l l y l a r g e , g i v e n t h e widespread d i s t r i b u t i o n of exposed b u i l d i n g s , i n f r a s t r u c t u r e components such as b r i d g e s and t r a n s m i s s i o n towers, and c u l t u r a l resources. P r i o r economic s t u d i e s i n d i c a t e d o l l a r l o s s e s due t o sulfur and s u l f a t e ambient concentrations CDuld amount t o as much as 2 b i l l i o n d o l l a r s annually (1). However, the poor q u a l i t y of the data a v a i l a b l e f o r these e a r l i e r s t u d i e s c l o u d s t h e c o n f i d e n c e one can place on these estimates. 2

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Current address: 707 Continental Circle, Mountain View, CA 94040 0097-6156/86/0318-0397506.00/ 0 © 1986 American Chemical Society

Baboian; Materials Degradation Caused by Acid Rain ACS Symposium Series; American Chemical Society: Washington, DC, 1986.

Downloaded by UNIV OF CALIFORNIA SANTA BARBARA on March 2, 2018 | https://pubs.acs.org Publication Date: September 25, 1986 | doi: 10.1021/bk-1986-0318.ch028

398

M A T E R I A L S D E G R A D A T I O N C A U S E D BY A C I D RAIN

A c c u r a t e q u a n t i f i c a t i o n of damages t o materials i s d i f f i c u l t . Most of t h e p r e v i o u s s t u d i e s u t i l i z e d a v a i l a b l e dose-response functions, which predict physical damage as a function of environmental variables. Translating the physical damage rates t o d o l l a r denominated losses required a d d i t i o n a l data on t h e s p a t i a l d i s t r i b u t i o n of p o l l u t a n t s and m a t e r i a l s a t r i s k and t h e m i t i g a t i v e behavior of consumers and businesses. S i g n i f i c a n t compromises were necessary i n p r e v i o u s e f f o r t s , due t o t h e i n c o m p l e t e n e s s of these data. For example, detailed geographic information on the amount of materials a t risk has generally not been available. In the absence of such detailed data, inventory estimates have sometimes been based on n a t i o n a l p r o d u c t i o n data. Since new, high r e s o l u t i o n d a t a has been a c q u i r e d i n t h e l a s t two years through t h e N a t i o n a l A c i d P r e c i p i t a t i o n Assessment Program (NAPAP), an assessment of the costs associated with increased maintenance can now be made which avoids compromises of t h i s kind. In t h i s study, the s p a t i a l resolution of damages i s 5 km., permitting a more accurate appraisal of the i n t e r actions between the d i s t r i b u t i o n of a i r q u a l i t y and material invent o r i e s than was previously possible. The new, higher q u a l i t y data do not resolve a l l the estimation d i f f i c u l t i e s , however. Because q u a n t i f i e d damage f u n c t i o n s a r e unavailable f o r some materials a t risk, comprehensive coverage i s s t i l l not p o s s i b l e . In a d d i t i o n , e s t i m a t i n g t h e a e s t h e t i c l o s s e s from t h e d e t e r i o r a t i o n of c u l t u r a l resources requires survey data, which are not available. Furthermore, major uncertainties i n the p h y s i c a l damage f u n c t i o n s a r e y e t t o be r e s o l v e d , and these uncert a i n t i e s a r e d i r e c t l y t r a n s l a t e d t o t h e f i n a l economic e s t i m a t e s . Thus, a t t h i s p o i n t i n time, t h e a n a l y s i s cannot d e f i n i t i v e l y e s t a b l i s h t h e magnitude of a l l adverse e f f e c t s ; the a n a l y s i s can, however, p r o v i d e a b e t t e r i n d i c a t i o n than h e r e t o f o r e p o s s i b l e of whether or not the material damages from a c i d deposition are economically important. The objective of t h i s paper i s t o present economic estimates of damage t o common construction m a t e r i a l s . The damage c a l c u l a t i o n s f o c u s d i r e c t l y on t h e damages t o m a t e r i a l - b u i l d i n g component combinations that can be a t t r i b u t e d t o exposure t o S 0 and wet a c i d i c d e p o s i t i o n . The e s t i m a t e s presented here c a p t u r e t o t a l damages associated with current loadings ( r e l a t i v e t o n a t u r a l background c o n c e n t r a t i o n s and pH) i n f o u r urban a r e a s i n t h e N o r t h e a s t e r n quadrant of t h e u n i t e d S t a t e s . G i v e n t h a t S 0 e m i s s i o n s can be reduced by no more than 50 percent a t a cost acceptable t o society i n t h i s century, l e s s than h a l f of the e s t i m a t e d damages a r e p o t e n t i a l l y recoverable as "be nef i t s " of a control e f f o r t . T h i s paper i s d i v i d e d i n t o t h r e e s e c t i o n s . In t h e f i r s t s e c t i o n , we o u t l i n e t h e conceptual b a s i s f o r v a l u i n g m a t e r i a l damages. The second s e c t i o n d e s c r i b e s t h e data, t h e computations, and the economic damage estimates f o r four case-study Metropolitan S t a t i s t i c a l Areas (MSAsX: New Haven, P i t t s b u r g h , C i n c i n n a t i , and P o r t l a n d , Maine. The l a s t s e c t i o n summarizes the r e s u l t s and provides some perspective on the uncertainties i n the analysis. 2

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The General Problem of Estimating Material Damages In broad terms, m a t e r i a l damages a r i s e when maintenance or r e p a i r costs increase, when there i s aesthetic degradation because maintenance i s postponed or not undertaken a t a l l , or when producers or



28.

LAREAUETAL.

Economic Assessment of Acid Damage

399

consumers substitute more expensive materials or processes t o o f f s e t the e f f e c t s of c o r r o s i o n or e r o s i o n on m a t e r i a l s . The conceptual economic framework o f f e r s a v a r i e t y of i n s i g h t s i n t o damage measurement issues and indicates the d i f f i c u l t y of comprehensive measurement of these damages, g i v e n a v a i l a b l e economic data. Only a b r i e f d i s c u s s i o n of the i n s i g h t s and l i m i t a t i o n s d e r i v e d from economic theory i s presented i n t h i s s e c t i o n . A more d e t a i l e d t h e o r e t i c a l treatment of t h i s subject can be found i n Horst e t a l . (2). Economists emphasize the concept of w i l l i n g n e s s t o pay i n the theory of value. T h i s r e f l e c t s the judgment t h a t the sum of the d o l l a r v o t e s of i n d i v i d u a l s best r e p r e s e n t s s o c i e t y ' s v a l u a t i o n of any good or s e r v i c e , whether t h a t good or s e r v i c e i s p r i v a t e or p u b l i c . A c r u c i a l d i s t i n c t i o n i s t h a t w i l l i n g n e s s t o pay i s not equal t o what one has t o pay, which i s an o b s e r v a b l e market r e s u l t . Rather, w i l l i n g n e s s t o pay can be i n f e r r e d from the i n f o r m a t i o n embedded i n the demand f u n c t i o n f o r a good or s e r v i c e . A market demand curve, D, shown i n p r i c e - q u a n t i t y space i n F i g u r e 1, r e p r e sents marginal w i l l i n g n e s s t o pay as a function of quantity. That i s , a consumer would be w i l l i n g t o pay a t most P Q f o r the qgth u n i t of the good. Total w i l l i n g n e s s t o pay i s represented by the area under the demand curve up t o a s p e c i f i e d q u a n t i t y . Frequently, only a p o r t i o n of t o t a l w i l l i n g n e s s t o pay i s relevant. When consumers pay f o r the good i n an e s t a b l i s h e d market, the f o c u s i s on consumer surplus, which nets purchase expenditures from t o t a l w i l l i n g n e s s t o pay. Consumer s u r p l u s , shown i n F i g u r e 1 as the a r e a e n c l o s e d by BpgC, thus r e p r e s e n t s what i n d i v i d u a l s a r e w i l l i n g t o pay over and above what they do pay. Consumer surplus i s only a part of measured s o c i e t a l well-being from which a change a t t r i b u t e d t o p o l l u t i o n can be computed. To describe the additional surplus value, i t i s necessary t o introduce a supply relationship. The supply curve, S, i n Figure 1 represents the incremental cost of producing one more unit of the good or service. At the market p r i c e , P Q , some p r o v i d e r s of the good w i l l be a b l e t o supply i t p r o f i t a b l y at a unit cost l e s s than p . This gives r i s e t o producer s u r p l u s , shown as the a r e a e n c l o s e d by ApgB i n F i g u r e 1. T h i s s u r p l u s r e p r e s e n t s the aggregate difference between p r i c e and marginal cost- Since producer surplus depicts the gain t o the owners of p r o d u c t i v e i n p u t s , i t i s added t o consumer s u r p l u s t o determine the t o t a l economic surplus that r e s u l t s from market a c t i v i t y . This t o t a l amount i s shown fcy area ABC i n Figure 1. To examine the e f f e c t of a c i d deposition on economic surplus, i t i s convenient t o focus on the market f o r "building services." (This argument i s v a l i d f o r user-related damages; i t does not account f o r the d i s u t i l i t y t o nonusers that may r e s u l t from aesthetic degradation of properties with c u l t u r a l or h i s t o r i c a l s i g n i f i c a n c e . ) B u i l d i n g s e r v i c e s , f o r both household and commercial p r o p e r t i e s , can be defined t o include both quantity and q u a l i t y dimensions. The p r i c e of building services would be the annualized l i f e - c y c l e cost of a maint a i n e d b u i l d i n g . T h i s p r i c e would i n c l u d e the c o s t s of p e r i o d i c maintenance, cleaning, and general upkeep. Starting from an en/ironmental s t a t e , ep, a s s o c i a t e d w i t h zero damages, i n c r e a s e d a c i d i c p o l l u t i o n , e p would increase the cost of b u i l d i n g services. This i s shown i n Figure 2 by the s h i f t i n supply from S(e ) t o Sie-^. As can be seen, the economic surplus decreases by the area ACDE. In t h i s application, a damage function methodology, rather than Q

0



400


Price

ys(e )

s p

0

i Β

q-L

Figure 2.

1

q

Q

Building Services

Surplus Change due t o P o l l u t i o n



28.

L A R E A U ET A L .


401

a w i l l i n g n e s s t o pay measure, i s used t o e s t i m a t e the monetary damages of i n c r e a s e d maintenance or replacement of b u i l d i n g mate rials. It i s important, therefore, t o examine how c l o s e l y measured maintenance or repair cost increases match the generalized b u i l d i n g service cost increase described above (area ACEE). Even under f a i r l y general conditions, the two are not the same, since the generalized c o s t change i s p r e d i c a t e d on a broad d e f i n i t i o n of c o s t s and b e h a v i o r a l f l e x i b i l i t y . The damage f u n c t i o n method, as g e n e r a l l y d e f i n e d , does not i n c l u d e the c o s t s of s u b s t i t u t i n g p o l l u t a n t - r e sistant materials t o mitigate damages, nor does i t account for l o s s of s e r v i c e a b i l i t y or aesthetic value. I f the increase i n maintenance c o s t i s based on computing the change i n maintenance frequency, l i t t l e b e h a v i o r a l f l e x i b i l i t y e x i s t s . The maintenance frequency depends on the time i t t a k e s t o reach the c r i t i c a l damage l e v e l , which i s determined by engineering standards and damage relationships assuming r e g u l a r maintenance p r a c t i c e . The problem w i t h t h i s approach i s that i n d i v i d u a l s may choose t o perform maintenance on a d i f f e r e n t schedule. One might expect the optimal l e v e l of mainten ance t o depend on a building's current usage and age, f o r example. •Hie biases r e s u l t i n g from physical and economic data l i m i t a t i o n s lead t o underestimates of economic damages i n some cases and over e s t i m a t e s i n o t h e r cases. Maintenance c o s t i n c r e a s e s w i l l over estimate actual damages i f behavioral f l e x i b i l i t y i s ignored, since p r o p e r t y owners would c o n s i d e r a l t e r n a t i v e s t o maintenance i f the a l t e r n a t i v e s were l e s s c o s t l y . On the other hand, the omissions, principally those associated with aesthetic values and the higher costs associated with substituting p o l l u t i o n - r e s i s t a n t materials e i t h e r a t the p o i n t of manufacture or a t the time of c o n s t r u c t i o n , l e a d t o u n d e r e s t i m a t e s of t o t a l damages. For example, g a l v a n i z e d gutters are more commonly used where a c i d i c deposition i s low, while more p o l l u t a n t - r e s i s t a n t vinyl-coated gutters are more p r i a i e n t i n high deposition regions (3). The cost associated with the p o l l u t i o n - r e s i s t a n t g u t t e r s i s not counted i n a c a l c u l a t i o n based s o l e l y on more frequent maintenance. Of g r e a t e r concern i s the n o n i n c l u s i o n of p o t e n t i a l l y important m a t e r i a l s a t r i s k , e.g. r e inforced concrete structures, automobile paints, and infrastructure materials. In sum, the l i m i t e d coverage of affected resources prob ably dominates other biases, though inaccuracies i n the measurement of p h y s i c a l damages and i n v e n t o r i e s of m a t e r i a l s a t r i s k a r e not inconsequential. Computing Construction Material Damages U s i n g p h y s i c a l damage f u n c t i o n s t o v a l u e i n c r e a s e d maintenance or more frequent replacement of b u i l d i n g components i n the presence of p o l l u t i o n requires the j o i n t a p p l i c a t i o n of the f o l l o w i n g data: ο D i s t r i b u t i o n of the pollutants, S0 and wet deposition of H , and other f a c t o r s , such as time of wetness, that enter i n t o dose-response functions. ο D i s t r i b u t i o n of resources a t r i s k . ο Cost of maintenance, r e p a i r , or replacement along w i t h other economic data t h a t i n d i c a t e how consumers and producers respond t o the more r a p i d d e t e r i o r a t i o n of building components. 2

+



402


The problem of estimating material damages using disaggregated data i s d i f f i c u l t . There a r e many d i f f e r e n t types of b u i l d i n g s , r e f l e c t i n g regional construction patterns and changes i n a r c h i t e c t ural s t y l e s over time. Each of these buildings contains a mixture of materials with v a r i e d s e n s i t i v i t i e s t o d i f f e r e n t pollutants. Thus, b u i l d i n g m a t e r i a l s and the damages t o them a r e not d i s t r i b u t e d u n i f o r m l y , e i t h e r w i t h i n urban areas or a c r o s s urban areas. For example, there i s more s t e e l i n central business d i s t r i c t s , and brick exteriors are more prevalent i n c i t i e s i n the Midwest than those on either coast, v a r i a t i o n s i n material s e l e c t i o n also seem t o r e f l e c t ambient p o l l u t i o n concentrations. There i s , f o r example, anecdotal evidence t h a t use of aluminum s i d i n g i s g r e a t e r i n a r e a s more s u s c e p t i b l e t o p o l l u t i o n - i n d u c e d p a i n t damage (3). G i v e n t h i s v a r i a b i l i t y i n m a t e r i a l usage, an a c c u r a t e e s t i m a t e of damages requires d e t a i l e d surveys t o estimate the d i s t r i b u t i o n of materials. Four MSAs i n the Midwest and N o r t h e a s t r e g i o n s — C i n c i n n a t i , Pittsburgh, New Haven, and Portland—were chosen f o r t h i s analysis. While material inventories w i l l be estimated f o r over 100 metropol i t a n a r e a s i n the f o r t h c o m i n g NAPAP Assessment, h i g h l y d e t a i l e d ground surveys were conducted i n 1984 by the Corps of Engineers only i n these f o u r c i t i e s (4). The r e s u l t i n g t a b u l a t i o n s of b u i l d i n g components (painted surfaces, gutters, etc.) by b u i l d i n g type (resid e n t i a l , commercial, e t c ) w i l l be used t o extrapolate materials usage i n the nonsampled MSAs. However, o n l y r e s u l t s i n the four c a s e study c i t i e s , where g r e a t e r a c c u r a c y i s p o s s i b l e , a r e r e p o r t e d i n this analysis. The b a s i c procedure i s o u t l i n e d i n F i g u r e 3. The f i r s t step, Inventory Accounting, u t i l i z e s randomly chosen 100 χ 100 f t . t o 400 χ 400 f t . " f o o t p r i n t s " of sampled d a t a on b u i l d i n g components. T h i s detailed inventory included approximately 1100 buildings i n the four c i t i e s . Surface area or l i n e a r footage was recorded by material type f o r e x t e r i o r w a l l s , r o o f s , g u t t e r s and downspouts, and f e n c i n g f o r a l l s t r u c t u r e s w i t h i n a g i v e n f o o t p r i n t . Window t r i m area was i n d i r e c t l y i n f e r r e d from the recorded a r e a of g l a s s . We used these data t o compute average material usage and p r o b a b i l i t i e s of occur rence for each material-building type combination. There were four b u i l d i n g categories: s i n g l e - f a m i l y residences, m u l t i p l e - f a m i l y r e s i d e n c e s , commercial and i n d u s t r i a l s t r u c t u r e s , and tax-exempt structures. Census and p r o p e r t y tax r e c o r d s a r e used t o o b t a i n a c c u r a t e counts of the numbers of b u i l d i n g s i n each category by census t r a c t f o r each of the f o u r case-study c i t i e s . A p p l y i n g the p r o b a b i l i t i e s and a r e a s of m a t e r i a l usage by b u i l d i n g type t o the census count of buildings allowed us t o extrapolate from the sampled data t o an estimate of the amount of b u i l d i n g material i n an e n t i r e metropolitan area (3). In the second step, Damage C a l c u l a t i o n s , shown i n F i g u r e 3, p h y s i c a l damage f u n c t i o n s f o r p a i n t (two types), z i n c g a l v a n i z e d m a t e r i a l , stone (marble and l i m e s t o n e ) , and mortar a r e used t o compute damage rates f o r each material. These damage functions have been developed from f i e l d and l a b o r a t o r y d a t a as w e l l as s t o i c h i o m e t r i c theory (see L i p f e r t e t a l . (5) f o r summary r e p o r t on m e t a l s ; Haynie (5) f o r p a i n t ; and Reddy e t a l . (7) f o r stone). The damage c o e f f i c i e n t s are summarized i n Table I, with lower- and upper-bound estimates provided f o r paint. These c o e f f i c i e n t s are used t o develop a range e s t i m a t e f o r monetary damages i n the t h i r d stage of the analysis.


28.

LAREAU ET AL.


Sampled Tract Inventory


(1) Inventory Accounting Extrapo lated Inven tory

Damage Function

A i r Quality Data

Damage Rate

(2) Damage Calculations

Service Lifetime Critical Damage Level Product Specification Changie i n Mainte inance Inter v a l

(3) Economic Calculations

D o l l a r Damage Computed

(4) Aggregation

Figure 3.

Replacement/ Repair Costs

Σ materials Σ tracts

Computation Flowchart


403

404


Table I: Estimation Assumptions

A. Damaqe C o e f f i c i e n t s 1. Paint —Carbonate S 0 —Carbonate H — S i l i c a t e S0 —Silicate H 2. Zinc —SO?

2


+

2

+

Low

Point

Hiqh

.0400 .0212 .0098 .0050

.1200 .0625 .0194 .0098 .5470 .1070 .3330 .2655 .1110 .0885

.1966 .1040 .0261 .0132

— —

3. Mortar—SO? —H 4. Stone —SO? -H

—

+

—

+

—

—

B. C r i t i c a l Loss Level Painted walls Painted gutters/downspouts Painted t r i m Mortar Stone Zinc gutters/downspouts Zinc fencing

—

— — — — — —

—

33.0um 19.1um 36.8um .375in .250in

— — — —

— — — —

—

—

229g/ne 229g/m

—

J

C. Repair/Replacement Costs ( $ / f t ) Painted walls 0.53 Painted gutters/downspouts 0.54 Painted t r i m 0.73 Mortar 2.58 Stone 0.00 Zinc gutters/downspouts 0.54 Zinc wire-mesh fencing 1.35 Zinc chain-link fencing 1.57

—

2

D. Carbonate-Silicate Paint S p l i t

.05

z

0.99 0.77 1.54 6.73 0.17 0.77 1.35 1.57

1.97 1.75 3.96 10.81 20.07 0.77 1.35 1.57

.15

.25

λ

a. Units: S0 , ug m ; H , ueq m yr ; paint erosion ug; zinc, g/nr; mortar/stone, um/yr. b. Reported c o s t s a r e n a t i o n a l averages; c o s t s f o r s p e c i f i c MSAs are adjusted f o r regional labor rates and other l o c a l factors. J

2

f

SOURCE: Mathtech (12), see text



28.

LA R EAU ET A L .

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Although t h e r e a r e many v a r i e t i e s of p a i n t i n use, Haynie (6) has chosen t o s i m p l i f y them into two types according t o the composi t i o n of the extender, or t h i c k e n e r . Of the two p a i n t types, the more p o l l u t a n t - r e s i s t a n t contains s i l i c a t e extenders w h i l e o l d e r , carbonate extender p a i n t s a r e l e s s p o l l u t a n t - r e s i s t a n t . S i l i c a t e extender p a i n t s have become dominant i n the e x t e r i o r p a i n t market o n l y i n the l a s t decade, a c c o u n t i n g f o r most (probably over 80 percent) of c u r r e n t s a l e s . The p r o p o r t i o n of s i l i c a t e p a i n t on buildings i s unknown, however, but i s conservatively assumed t o be 85 percent. The switch t o s i l i c a t e paints may have occurred p a r t i a l l y as a result of concern with the environmental s u s c e p t i b i l i t y of the carbonate extender paints. These s u b s t i t u t i o n costs are not factored i n t o the damage estimates provided i n t h i s analysis. A i r q u a l i t y data f o r S 0 , wet d e p o s i t i o n of H , and other g e n e r a l environmental d a t a a r e i n p u t s t o the damage f u n c t i o n s . For the r e s o l u t i o n l e v e l r e q u i r e d f o r reasonable o v e r a l l accuracy, monitored d a t a a r e inadequate so t h a t modeled d a t a a r e developed u s i n g d i s p e r s i o n a l g o r i t h m s . Damages a r e computed f o r 5 km. g r i d s w i t h i n the defined boundaries of each metropolitan area. "Local" S 0 c o n c e n t r a t i o n s were c a l c u l a t e d u s i n g e m i s s i o n sources w i t h i n an envelope d e f i n e d by a 50 km. boundary around the m e t r o p o l i t a n a r e a (8). The "nonlocal" contribution of S 0 was determined from ASTRAP model runs (provided by J . Shannon a t Argonne N a t i o n a l L a b o r a t o r y ) . F i n a l l y , H deposition was measured from regionally monitored data. The damage rate, i n weight or l i n e a r l o s s units, i s used i n the Damage C a l c u l a t i o n stage of Figure 3 t o compute the number of years u n t i l the c r i t i c a l damage l e v e l (defined as the l e v e l of damage a t which maintenance or replacement i s r e q u i r e d ) i s reached. As pollutant loadings increase, the time i n t e r v a l between required maintenance or replacement decreases, and maintenance costs go up. The c r i t i c a l damage l e v e l i s determined i n one of two ways. One, t h e c r i t i c a l l o s s of m a t e r i a l t h i c k n e s s i s s p e c i f i e d by i n d u s t r y standards or by m a t e r i a l s s p e c i a l i s t s . Two, the c r i t i c a l damage l e v e l can be computed from service l i f e t i m e information and knowledge of current p o l l u t i o n l e v e l s . The c r i t i c a l damage l e v e l s used i n t h i s stage of the a n a l y s i s are summarized i n Table I. Economic damages are computed i n the t h i r d stage shown i n Figure 3. The b a s i s f o r economic damages i s the i n c r e a s e d maintenance, repair, or replacement of b u i l d i n g components under current p o l l u t i o n loadings r e l a t i v e t o p r i s t i n e conditions (S0 a t .5ug/m and a pH of 5.2). Annual monetary damages a r e computed f o r each m a t e r i a l component as the product of t h r e e f a c t o r s : the c o s t per u n i t a r e a ( $ / f t ) , the exposed area i n the inventory ( f t ) , and the maintenance time i n t e r v a l difference predicted from the damage function and the c r i t i c a l damage l e v e l ( y r " ) . The t h i r d factor e f f e c t i v e l y d i s t r i butes the a d d i t i o n a l cost of maintenance uniformly over the reduced maintenance i n t e r v a l . These annual c o s t s represent damages i n the 1980's, but because long-term l i f e - c y c l e considerations have not been taken f u l l y i n t o account, the estimates may not be representative of f u t u r e annual damages. A l l c a l c u l a t i o n s a r e made f o r the e x i s t i n g stock of materials, assuming no net growth i n t h i s stock. Furthermore, a l l buildings are assumed t o be o p t i m a l l y maintained i n the future. The underlying maintenance cost data are summarized i n Table I. +

2

2

2

+

3

2

2

2

1



406


Maintenance and replacement c o s t data were o b t a i n e d from i n d u s t r y manuals, such as Robert Snow Means Co. (9), and from a NBS study (10). Lower- and upper-bound estimates of unit costs are provided t o f a c i l i t a t e computation of range estimates of the economic damages. For repainting, the low unit cost assumption r e f l e c t s the a p p l i cation of a primer and one surface coat of paint. The midpoint u n i t cost assumption includes minimal surface preparation and two surface c o a t s , w h i l e the h i g h e s t i m a t e i n c l u d e s a d d i t i o n a l s c r a p i n g and sanding p r e p a r a t i o n c o s t s . The r e p a i n t i n g e s t i m a t e s f o r s i n g l e f a m i l y u n i t s have been a d j u s t e d t o account f o r " d o - i t - y o u r s e l f " labor, which had the e f f e c t of lowering homeowner painting costs by 18 percent. Galvanized gutters/downspouts are assumed t o be painted once the z i n c c o a t i n g f a i l s . G a l v a n i z e d f e n c i n g i s assumed t o be replaced when the c r i t i c a l damage l e v e l i s reached. The cost of repointing mortar was based on d e t a i l e d case studies of r e h a b i l i t a t i o n of several buildings i n New York C i t y (11). unlike p a i n t or g a l v a n i z e d m a t e r i a l s , mortar and stone m a t e r i a l f a i l u r e s occur over long time p e r i o d s . Thus, annual maintenance c o s t s may need t o be a d j u s t e d by a d i s c o u n t f a c t o r , even g i v e n an i m p l i e d assumption of constant h i s t o r i c a l and f u t u r e emissions. With rep o i n t i n g of mortar o c c u r r i n g a t roughly 50 year i n t e r v a l s and many older buildings exposed t o comparable (or higher) p o l l u t a n t loadings, p o l l u t i o n - a s s o c i a t e d mortar r e p a i r i s a l r e a d y a r e a l i t y . Thus, unadjusted annual c o s t e s t i m a t e s a r e a p p r o p r i a t e . For stone the s i t u a t i o n i s q u i t e d i f f e r e n t . The replacement p e r i o d f o r facade stone, under c u r r e n t p o l l u t a n t c o n d i t i o n s , i s hundreds of years. B u i l d i n g s u s i n g t h i s m a t e r i a l , e.g. s k y s c r a p e r s , are a l l l e s s than 100 y e a r s o l d . Thus, damages w i l l not be r e a l i z e d f o r a l o n g time. For t h i s reason, the low and m i d p o i n t u n i t c o s t e s t i m a t e s a r e d i s counted. A l l the cost estimates are adjusted t o 1984 d o l l a r s and t o the c i t y construction p r i c e index f o r the appropriate MSA. The f i n a l s t e p i n the p r o c e s s i l l u s t r a t e d i n F i g u r e 3 i s the aggregation over building components, b u i l d i n g types, and the 5 km. grids, t o estimate t o t a l damages i n each of the four c i t i e s . Case-Study Damage Estimates and

Findings

The r e s u l t s are summarized i n Table II. Monetary estimates of annual damages a r e shown by c i t y as a f u n c t i o n of m a t e r i a l , b u i l d i n g type and p o l l u t a n t source. The estimates are presented i n range form using the assumptions l i s t e d i n Table I. E s s e n t i a l l y , three main sources of u n c e r t a i n t y a r e captured i n the range e s t i m a t e s : uncertain physical damages, an uncertain s p l i t between carbonate and s i l i c a t e paint extenders, and uncertain maintenance and replacement costs. I t i s c l e a r from Table I I that while the r e l a t i v e damages among the c i t i e s vary, the p o t e n t i a l d o l l a r amounts are large. In j u s t the four case-study MSAs, the t o t a l annual damages amount t o approximatel y $130 m i l l i o n . On a per c a p i t a b a s i s , these damages range from a p p r o x i m a t e l y $8 t o $43 i n the f o u r case-study c i t i e s , w i t h Pittsburgh the highest and Portland the lowest. Much, but not a l l , of the v a r i a t i o n among the c i t i e s can be explained by differences i n the average size of buildings, by regional material usage, e s p e c i a l l y f o r w a l l s , and by the r e l a t i v e s i z e of the c o m m e r c i a l / i n d u s t r i a l sector. In addition, the p o l l u t a n t l e v e l s vary among the case-study cities. Thus, i t i s not s u r p r i s i n g that Pittsburgh with many large


28.


L A R E A U ET A L .

407


Table I I : Summary of Damage Estimates f o r Four Case-Study MSAs

ANNUAL DAMAGE IN MILLIONS OF 1984 DOLLARS BY SECTOR, MATERIAL, AND POLLUTANT SOURCE. One-year damages a r i s e from i n c r e a s e d c o s t s associated with reduced maintenance/replacement i n t e r v a l s a t ambient relative to "pristine" pollutant levels. Low e s t i m a t e r e f l e c t s m i n i m a l maintenance, low damage c o e f f i c i e n t , and 95% s i l i c a t e assumptions. High e s t i m a t e r e f l e c t s e x t e n s i v e maintenance, h i g h damage c o e f f i c i e n t , and 75% s i l i c a t e assumptions. V a r i a t i o n i n damages i s explained by differences i n average b u i l d i n g size, l o c a l material usage, size of industrial/commercial sector, and pollutant levels.

Annual Damage ($10°) Low

Point

High

Cincinnati Paint Mortar & Stone Zinc

3.2 3.0 2.1

18.6 8.3 2.7

77.5 16.4 2.7

Single-family Multi-family Commercial/Industrial Tax-exempt

4.1 0.9 2.7 0.6

15.0 4.0 9.0 1.7

50.8 13.6 27.7 4.4

Local S 0 Nonlocal S 0 H

1.6 2.4 4.0

5.9 9.6 14.1

19.8 31.2 45.1

8.3 6.

29.6 22.

96.6 69.

Paint Mortar & Stone Zinc

0.7 0.3 0.2

3.7 0.7 0.3

15.3 1.5 0.3

Single-family Multi-family Ccmmercial/Industrial Tax-exempt

0.6 0.2 0.1 0.2

2.8 1.0 0.4 0.5

10.9 3.5 1.5 1.3

Local S 0 Nonlocal S 0 H

0.1 0.4 0.6

0.5 1.8 2.3

1.8 6.7 8.7

1.1 2.

4.8 11.

17.2 34.

2

2

+

Total Per Capita

($)

New Haven

2

2

+

Total Per Capita

($)

(Table I I continued on following page)


408


Table I I .

Continued 6

Annual Damage ($10 ) Low

Point

High

Paint Mortar & Stone Zinc

10.8 9.0 5.9

61.2 24.9 9.8

248.6 49.0 9.8

Single-family Multi-family Commercial/Industrial Tax-exempt

6.4 2.8 15.5 1.0

24.6 10.6 56.9 3.8

77.6 33.0 185.3 11.4

5.8 9.0 9.7

22.6 35.2 36.1

74.5 116.8 114.0

25.7 12.

95.9 43.

307.3 138.


Pittsburgh

Local S 0 Nonlocal SO? H 2

+

l

Total Per Capita ($)

Portland Paint Mortar & Stone Zinc

0.2 0.1 0.1

1.2 0.3 0.1

5.0 0.5 0.1

Single-family Multi-family Commercial/Industrial Tax-Exempt

0.2 0.1 0.1 0.0

0.9 0.3 0.3 0.1

3.4 1.1 0.8 0.3

Local S 0 Nonlocal SO? H

0.0 0.1 0.2

0.2 0.5 0.9

0.7 1.7 3.3

Total Per Capita

0.4 2.

1.6 8.

5.7 29.

2

+

($)

SOURCE: Mathtech (12)


LAREAU ET AL.

28.

409


buildings and high S 0 l e v e l s has higher damages, both t o t a l and per capita, than Portland. S e v e r a l other f i n d i n g s a r e i l l u s t r a t e d i n T a b l e I I . Most obvious i s the importance of paint i n t h i s analysis, accounting f o r w e l l over h a l f of t o t a l damages i n each of t h e f o u r case-study cities. P a i n t damages a r e l e s s dominant o n l y i n t h e u n l i k e l y s i t u a t i o n (i.e., with a low subjective probability) that the lowerbound estimate with a low damage c o e f f i c i e n t , no surface preparation, and a 95-5 p e r c e n t s i l i c a t e - c a r b o n a t e p a i n t s p l i t i s a c t u a l l y correct. Mortar damages a r e t h e second most s i g n i f i c a n t category, i n c r e a s i n g i n importance f o r c i t i e s , l i k e C i n c i n n a t i , t h a t a r e further west. In the larger c i t i e s , e.g. Pittsburgh, the commercial/ i n d u s t r i a l sector accounts f o r the l a r g e s t proportion of damage; i n s m a l l e r c i t i e s , t h e g r e a t e s t p r o p o r t i o n of damage o c c u r s i n the single-family residence b u i l d i n g category. Damages t o s i n g l e - f a m i l y r e s i d e n c e s may be more c e r t a i n than damages t o other types of buildings, given the presumption of "ownership pride" and concern of appearances on t h e p a r t o f home owners. Thus, t h e assumption of r e g u l a r maintenance i s probably c l o s e t o t h e mark so t h a t t h e damages a r e r e l a t i v e l y c e r t a i n . In c o n t r a s t , changes i n l o c a l business conditions can sometimes lead t o unexpectedly shorter economic l i f e t i m e s for c o m m e r c i a l / i n d u s t r i a l b u i l d i n g s , and f o r these b u i l d i n g s maintenance on a continuous " o p t i m a l " schedule i s l e s s l i k e l y , and damages are consequently l e s s c e r t a i n . F i n a l l y , as i n d i c a t e d i n Table I I , " l o c a l " SOo sources account for a f a i r l y small f r a c t i o n of t o t a l damages—less than 25 percent i n each of t h e f o u r c i t i e s . Apparently, t h e C l e a n A i r A c t has e f f e c t i v e l y reduced SOo l e v e l s i n major c i t i e s t o the point where nonlocal S 0 damages and carnages associated with wet deposition are f a r more important than damages a t t r i b u t e d t o l o c a l sources. Two general observations on how these r e s u l t s should be i n t e r p r e t e d a r e worthy of emphasis. F i r s t , t h e c u r r e n t t o t a l damage e s t i m a t e s r e p o r t e d here r e p r e s e n t damages associated with ambient p o l l u t i o n loadings; thus, any p r a c t i c a l reductions of emissions w i l l o n l y buy a p a r t i a l r e d u c t i o n of these damages. These damages represent losses a t t h i s point i n time; future damages could be lower i f , f o r example, t h e s i l i c a t e extender share of t h e p a i n t market increases. Second, as i s apparent from the order of magnitude span between the low and high estimates, considerable uncertainty i s present i n the analysis. Much of the uncertainty associated with the increased maintenance and replacement costs of the materials f o r which doseresponse f u n c t i o n s were a v a i l a b l e has been captured i n t h e range estimates. Nonetheless, there a r e a d d i t i o n a l unquantif ied uncertainties. None of t h e damage f u n c t i o n s has been developed from, or checked a g a i n s t , a c t u a l d e t e r i o r a t i o n r a t e s on r e a l b u i l d i n g s . In addition, most of the damage i s t o paint, f o r which the uncertainty i s p a r t i c u l a r l y large, e s p e c i a l l y with respect t o the H p o r t i o n of the dose-response function. F i n a l l y , the estimates presented here do not f u l l y capture s o c i e t y ' s w i l l i n g n e s s t o pay t o a v o i d m a t e r i a l damages. Only repair and replacement costs are estimated; aesthetic l o s s e s a r e ignored. F u r t h e r , t h e e s t i m a t e s a r e not comprehensive. M a t e r i a l s such as a u t o m o b i l e p a i n t s and c o n c r e t e have not been i n cluded i n t h i s analysis. Material usage i n some sectors, e.g. s t r u c tures such as bridges and rural areas, have a l s o been excluded.


2

2

+


410

M A T E R I A L S D E G R A D A T I O N C A U S E D BY A C I D R A I N

While the caveats l i s t e d above should not be underestimated, we believe that t h i s analysis provides more convincing evidence than was h e r e t o f o r e a v a i l a b l e t h a t damages t o m a t e r i a l s from a c i d i c a i r p o l l u t a n t s are economically important. This outcome i s a t t r i b u t e d t o improvements i n t h e d a t a d e s c r i b i n g t h e j o i n t d i s t r i b u t i o n of materials and a i r p o l l u t a n t s and i n the damage functions. The noncomprehensive coverage of sectors and materials and the substantial uncertainty reported are strong arguments f o r further research.


Acknowledgments This research was conducted as part of the National Acid P r e c i p i t a t i o n Assessment Program (NAPAP) from which most of the data were obtained. The views expressed i n t h i s paper are those of the authors and do not n e c e s s a r i l y r e f l e c t those of NAPAP or i t s s u p p o r t i n g agencies. Literature

Cited

1. Freeman, Μ. Α.; "Air and Water Pollution Control"; John Wiley & Sons, New York, NY, 1982; pp. 91-100. 2. Horst, R. L.; Manuel, E. H.; Bentley, J. T.; "Economic Benefits of Reduced Acidic Deposition on Common Building Materials: Methods Assessment"; Mathtech Inc., Report prepared for Office of Policy Analysis, U.S. Environmental Protection Agency, 1984. 3. Novak, K. M.; Coveney, Ε. Α.; Torpey, M. R.; Lipfert, F. W.; "Data Bases on Residential Construction Practice"; Brookhaven National Laboratory, 1984. 4 Merry, C.; LePotin, P.; "A Description of New Haven, Conn. Building Data Base"; U.S. Army Corps of Engineers Report, 1985. 5. Lipfert, F.; Benarie, M.; Daum, M.; "Derivation of Metallic Corrosion Damage Functions for Use in Environmental Assessments"; Brookhaven National Laboratory, 1985. 6. Haynie, F.; "Atmospheric Damage to Paints"; EPA Environmental Research Brief, EPA/600/M-85/019, 1985. 7. Reddy, M.; Sherwood, S.; Doe, B.; "Limestone and Marble Dis solution by Acid Rain"; Proceedings of 5th International Congress on Deterioration and Conservation of Stone, 1985. 8. Lipfert F.; Dupuis, L.; Schaedler, J.; "Methods for Mesoscale Modeling for Materials Damage Assessment"; Brookhaven National Laboratory, 1985. 9. Robert Snow Means Co.; "Repair and Remodeling Cost Data: Com mercial/Residential 1983"; Kingston, MA. 10. Weber, S.; Lippiatt B.; Wiener, M.; "A Life-Cycle Cost Data Base for Assessing Acid Deposition Damage to Common Building Mate rials"; National Bureau of Standards, Department of Commerce, 1985. 11. Ottavino, K.; Prudon, T.; "Facade Repair: New York City Case Studies"; Brookhaven National Laboratory, Report prepared for National Park Service, 1985. 12. Mathtech Inc.; "A Damage Function Assessment of Building Materials: The Impact of Acidic Deposition"; Report prepared for Office of Policy Analysis, U.S. Environmental Protection Agency, 1985. RECEIVED January 13, 1986


Model for Economic Assessment of Acid Damage to Building Materials

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