One Big Fish by zhp16666


									ESSAY                                                                                                                                                                                                                          ESSAY

                                                                                                              ighting professionals are            This incident was quickly seized        used by infants, small children or
                                                                                                              presumably         aware    that   upon as an argument against the           pregnant women…” and, should a
                                                                                                              used CFLs are supposed             use of CFLs. Why should consum-           lamp be broken over a carpet, that

     Dangerous                                                                                        to be recycled, and not just sent
                                                                                                      to landfills, because of the small
                                                                                                                                                 ers bear the risk of introducing a
                                                                                                                                                 potential safety hazard into their
                                                                                                                                                                                           “…homeowners consider removal
                                                                                                                                                                                           of the area of the carpet where the

     Mercury in cFLs?
                                                                                                      amount of toxic mercury they con-          own homes just to save a little           breakage occurred as a precaution,
                                                                                                      tain. But what do you advise your          energy? Against health concerns           particularly in homes with infants,
                                                                                                      clients when they break a lamp?            and clean-up costs on this scale, a       small children, or pregnant wom-

     One Big Fish
                                                                                                      And just how dangerous is the              lower utility bill and the satisfac-      en.” This is not much better than
                                                                                                      mercury inside?                            tion from a little environmental-         the $2,000 clean-up, and, if taken
                                                                                                        You may have heard that clean-           ism seem meager encouragement.            seriously, is likely to discourage
                                                                                                      up costs are exorbitant and that the       In response to public outrage, es-        a lot of people from considering
                                                                                                      mercury vapor concentration from           pecially in the blogosphere, MDEP         CFLs at all.

                                                                                                      a broken lamp is unsafe. Actually,         posted a reply documenting its
                                                                                                      the amount of mercury that you are         assurances to Bridges that, in her        a QuesTion oF eXPosure
                                                             By RoBeRt CleaR, FRanCis RuBinstein      likely exposed to after breaking a         case, “potential mercury exposure           Those of us who remember

                                                             and JaCk Howells                         lamp is no more than you subject           would be very low and likely of           mercury    thermometers,          which
                                                                                                      yourself to when eating a bite of          negligible health concern.” Un-           contained 100 or more times the
                                                                                                      tuna. In this paper, we review the         fortunately, this assurance is ap-        amount of mercury in a CFL, may
                                                                                                      concerns, describe why we believe          parently true only as long as bro-        well wonder how we ever sur-
                                                                                                      that the fish comparison is valid and      ken CFLs are “properly cleaned            vived. In fact, the use of the state
                                                                                                      show that the real risk is negligible.     up.”   [2]
                                                                                                                                                              These responses are hardly   air quality standard to determine
                                                                                                        Let’s start with the reports of ex-      less alarming. Would exposure be          the acceptable level for a one-time
                                                                                                      orbitant clean-up costs and danger-        potentially hazardous under dif-          or infrequent exposure is extreme-
                                                                                                      ous mercury vapor levels. In April         ferent circumstances? And what            ly conservative. The state standard
                                                                                                      2007, Brandy Bridges accidentally          does proper clean-up entail?              is based on an estimate of the No
                                                                                                      broke a CFL in her daughter’s bed-           MDEP couldn’t find the informa-         Observable Adverse Effects Level
                                                                                                      room and was left wondering what           tion to actually answer these ques-       (NOAEL)        for   continuous   (life-
                                            grams                                                     to do next.         After several refer-   tions, so they ran a study which          time) exposure. The MDEP justi-
                                   48 micro
        6 oz. tu na fish sa         .07 micro
                                              grams                                                   rals, she phoned the Maine Depart-         examined 45 different breakage/           fies using this ambient air quality
         typica l CFL brea                                                                            ment of Environmental Protection           clean-up scenarios. [3] They found        (AAQ) standard for a single expo-
                                                                                                      (MDEP), which sent a specialist            that altering the ventilation condi-      sure because of a lack of informa-

                                                      the potential perils have been played           to her home a day later. Airborne
                                                                                                      concentrations of mercury were
                                                                                                                                                 tions, cleaning methods and equip-
                                                                                                                                                 ment, sample CFL, and breakage
                                                                                                                                                                                           tion on the effects of prenatal ex-
                                                                                                                                                                                           posure: “An important issue for
                                                      up in the press, but if simple common           generally low, but measurements            conditions and surface (e.g., hard-       which there are no data is the rela-

                                                      sense is used when disposing of a               in two areas—a 1-ft area around
                                                                                                      the breakage and a nearby bag of
                                                                                                                                                 wood floor versus carpet), result-
                                                                                                                                                 ed in average first-hour mercury
                                                                                                                                                                                           tive importance of a short spike
                                                                                                                                                                                           in exposure versus a longer-term
                                                      broken CFL, the resulting exposure              toys where some lamp fragments             vapor concentrations that varied          lower exposure in producing tox-

                                                      to mercury is equivalent to a mere              had fallen—exceeded the state’s air
                                                                                                      quality standard. When Bridges
                                                                                                                                                 by a factor of 600. Many of these
                                                                                                                                                 concentration levels exceeded the
                                                                                                                                                                                           icity. The U.S. EPA considers that a
                                                                                                                                                                                           single exposure may be sufficient
                                                      nibble of tuna                                  expressed concern about long-              state air quality standard, and the       to produce effects in a developing
                                                                                                      term exposure, she was referred            report concluded that “…home-             organism because of the recogni-
                                                                                                      to a commercial clean-up contrac-          owners consider not utilizing fluo-       tion of potential critical windows
                                                                                                      tor; the estimate for a professional       rescent lamps…where they could            of vulnerability.” Based on this
                                                                                                      clean-up was $2,000.                       easily be broken, in bedrooms             logic, a short spike in exposure

52                                                                               LD+A August 2009                                                                                                                53

      could be as short as a single breath.            within tissues in the body, and is         a past history of eating fish, to the
      MDEP, without any discussion of                  only gradually released over time.         dose from a broken CFL therefore
      the issue, confines its analysis to              Prenatal exposure actually results         becomes a useful, while conserva-
      situations where the average level               from the combination of mercury            tive, exercise in understanding the
      exceeds the AAQ for one hour.                    from the environment and any               real danger posed by CFLs.
        The problem with applying this                 mercury remaining in the blood-              For those following an “aver-
      principle to air concentrations is               stream from a history of exposure.         age” diet, fish is one of the most
      that exposure is not directly pro-                 While the various forms of mer-          common sources of mercury that
      portional to the current air con-                cury appear to have similar mech-          we are exposed to in everyday life.
                                                                                                  The amount of methylmercury
                                                                                                  that accumulates in fish varies ac-
      Those of us who remember mercury                                                            cording to how high the fish is on
      thermometers, which contained 100 or more                                                   the food chain (Figure 1) [4] . The
                                                                                                  FDA encourages people, including
      times the amount of mercury in a CFL, may                                                   pregnant women, to eat fish, but
      well wonder how we ever survived                                                            recommends that they eat no more
                                                                                                  than one 6-ounce meal per week of
      centration. Human beings are con-                anisms of toxicity, methylmercury          fish such as Albacore tuna, which
      tinually exposed to mercury—from                 is the most dangerous for the pre-         is relatively high in mercury con-
      inorganic mercury salts in food                  natal or young infant; it readily          tent. Albacore tuna is one of the
      and water, elemental mercury in                  crosses the placental and blood-           most commonly consumed fish.
      air (from natural and anthropo-                  brain barriers and is much more              Figure 2 shows the key compar-
      genic sources), and organic mer-                 likely to be bound to the developing       isons between mercury exposures
      cury,   such       as   methylmercury,           brain. [4-6] Comparing the mercury         from breaking a CFL, and the
      in fish. Mercury becomes bound                   dose from a meal of fish, or even          methylmercury exposures from
                                                                                                  eating Albacore tuna. The top bar,
       Figure 1 : Methylmercury concentrations in 18 types of commonly consumed fish, showing     showing the tiny mercury dose
       average (black dots) and range (orange bars). [7] Source: U.S. Dept. of Health and Human
                                                                                                  (0.068   micrograms)     calculated
       Services and U.S. Environmental Protection Agency, “Mercury Levels in Commercial Fish
                                                                                                  from the median of the 45 break-
       and Shellfish.”
                                                                                                  age scenarios, is compared to the
                                                                                                  dose absorbed by breathing air
                                                                                                  contaminated at the state air qual-
                                                                                                  ity standard for one hour (0.153
                                                                                                  micrograms) and eight hours (1.22
                                                                                                  micrograms). (Eight hours is an
                                                                                                  approximate upper limit on the
                                                                                                  time it takes to digest and absorb
                                                                                                  the mercury from a meal.) Most
                                                                                                  important in this comparison is
                                                                                                  the bar showing the dose from
                                                                                                  eating a single (6-ounce) meal of
                                                                                                  Albacore tuna (48 micrograms of
                                                                                                  mercury), which is roughly equal
                                                                                                  to the very worst CFL breakage
                                                                                                  case measured by the MDEP. The


                                          Figure 2: Dose of mercury from listed exposures.
last, and by far the largest, of the
bars is the steady state body bur-
den that would result if the recom-
mended amount of fish is regularly
consumed on a weekly basis.

  So what do all these compari-
sons mean? First, they show that
if simple common sense is used
in disposing of the broken CFL,
the resulting exposure to mercury
is equivalent to about 1/50 th of an
ounce—a single nibble—of Albacore
tuna! Second, when we account for
the fact that methylmercury ap-
pears to be more hazardous than
an equivalent amount of mercury         average the recommended amount                   number of cases from overdoses
vapor, they suggest that the state      per week.” [8] .                                 of aspirin and other household
air quality standard (which is only       Note that the worst case scenar-               medicines, as well as many house-
marginally higher than a nibble of      io was truly designed as the worst               hold chemicals. We found fewer
tuna) is an inappropriately conser-     of worst cases. It yielded 800 times             cases of mercury poisoning from
vative standard for a single short-     the median dose, and five times the              paint, from broken thermometers
term exposure. Third, even the          dose of the second worst case (data              or medical equipment, and from
most extreme CFL breakage sce-          not shown in Figure 2). There were               people attempting to refine gold or
nario measured by the MDEP only         two main factors that contributed                extract silver from dental fillings.
equaled the approximate exposure        to this case. First, every effort was            We found only one case involving
from a single meal of fish. Fourth,     made to force the mercury into the               mercury from lamps, and that re-
the equilibrium body burden that        air. Although the bulk debris was                sulted from the breakage of an en-
would result from long-term con-        picked up, it was disposed of in a               tire carton of older 8-ft lamps. An
sumption of the recommended             trash can, in the room. A vacuum                 infant playing for several months
amount of fish is about 10 times        cleaner, with a beater attachment,               in a shed where the lamps were
larger than the very worst case         was then used on the carpet where                broken developed acrodynia, a
CFL breakage scenario. The incre-       the lamp had been broken and                     condition primarily characterized
mental dose from a single meal is       then left in the room. Second, en-               by irritability, anorexia and pain
only a fraction of the total dose due   trances to the room were shut, and               in the extremities. [9] The condi-
to long-term exposure. The FDA          heating vents and windows sealed,                tion cleared up after the infant
explicitly bases its recommenda-        leaving little chance for the mer-               was removed from exposure to
tions on fish consumption with this     cury to disperse. The important                  the mercury spill. This case was
in mind: “One week’s consumption        point here: all of these factors are             not equivalent to the breaking of
of fish does not change the level of    easily avoidable.                                one, or even several, CFLs. Old 8-
methylmercury in the body much            It is an unfortunate fact of life              ft lamps contain 10 to 50 times as
at all. If you eat a lot of fish one    that people are exposed to many                  much mercury as new CFLs, so the
week, you can cut back for the next     toxins, sometimes with tragic con-               amount of mercury released in this
week or two. Just make sure you         sequences. We found an immense                   case was several hundred to 1,000

LD+A	August	2009	                                                                                                               55

        times more than would be released                          1975 and continues to work part time on window and
                                                                   lighting issues at Berkeley Lab since retiring in 1997.
        by a single broken CFL.
                                                                                       Francis Rubinstein, Fellow IES
                                                                                       (Member 2003), received his
        WHAT DO YOU SAY?                                                               B.A. in Physics from University
           So your client is concerned about                                           of California at Berkeley in 1977.
        what might happen if they break a                                              He has been a staff scientist in
                                                                   the Environmental Energy Technologies Division at
        CFL. What do you tell them? You
                                                                   Lawrence Berkeley National Laboratory since 1979,
        can tell them that if they follow                          where he now leads the Lighting Group. The focus of
        the steps described below a bro-                           his research at Berkeley Lab has been in the area of
        ken CFL poses about as much of a                           advanced communications techniques for the control
        health risk as a bite of tuna.                             of lighting systems in buildings.
                                                                   Jack Howells is currently an undergraduate in English
           1) Ventilate the area where the
                                                                   at UC Berkeley and is also a student assistant at Law-
        lamp is broken with outside air,                           rence Berkeley National Laboratory.
           2) Promptly clean up and remove
                                                                   [1] “Fluorescent Bulb Break Creates Costly Has-
        any visible debris to a ventilated
                                                                   sle,” The Ellsworth American, April 12, 2007:
        (preferably outdoor) area,                       
           3) Vacuuming forces mercury                             com_content&task=view&id=7446&Itemid=31

        into the air and should be avoided
                                                                   [2] The Department of Environmental Protection
        if possible. (Any vacuuming should                         (DEP) facts regarding the Prospect Maine Compact
                                                                   Fluorescent Lamp breakage:
        be limited to one or two minutes,
                                                                   w w / dep / r wm / homeowner/ pdf /
        and the vacuumed space should be                           prospecthistory.pdf
        vacated, while ventilating, for one
                                                                   [3] Maine Compact Fluorescent Lamp Study, Febru-
        to two hours. In addition, the vac-
                                                                   ary, 2008:
        uum cleaner should be emptied,                             cflreport.htm

        then used and stored in ventilated
                                                                   [4] Toxicological Profile for Mercury, U. S. Depart-
        areas until it has been used several                       ment of Health and Human Services, March 1999:
        more times.)                                     

           If they have already broken the
                                                                   [5] Ministry of the Environment, Government of
        lamp and vacuumed it up and are                            Japan, Minimata Disease The History and Measures
        worried, you can tell them that they
        have been exposed to about as much                         [6] Yukio Takizawa and Akira Sekikawa, “Super-
        mercury as they would get from eat-                        course Epidemiology of Minimata Disease,” page 16
        ing the FDA recommended amount
        of fish per week. They can reduce                          [7] U.S. Department of Health and Human Services
                                                                   and U.S. Environmental Protection Agency, “Mer-
        any potential risk to a prenatal in-
                                                                   cury Levels in Commercial Fish and Shellfish,”
        fant by limiting their fish intake over                    Last updated Feb. 2006
        the next couple of weeks.                        

           And no, they shouldn’t call for
                                                                   [8] What You Need to Know About Mercury in Fish
        HazMat.                                                    and Shellfish, 2004 EPA and FDA Advice For: Wom-
                                                                   en Who Might Become Pregnant, Women Who are
                                                                   Pregnant, Nursing Mothers, Young Children:
                            About the Authors: Robert
                            Clear, Fellow IES (Member 1984)
                            received his Ph.D. in Chemistry        [9] Tunnessen WW Jr, McMahon KJ, Baser M. “Acro-
                            from University of California at San   dynia: Exposure to Mercury from Fluorescent Light-
                            Diego in 1975. He has been a staff     bulbs.” Pediatrics 79 (5): 786-9. (1987) PMID 3575038.

        scientist in the Environmental Energy Technologies Di-
        vision at Lawrence Berkeley National Laboratory since


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