From: "Higgins, Cortney" <Cortney_Higgins@omb.eop.gov> 

To: Sharon Nizich/RTP/USEPA/US@EPA 

Cc: Steve Fruh/RTP/USEPA/US@EPA, JohnB Chamberlin/DC/USEPA/US@EPA 

Date: 11/22/2010 11:55 AM 

Subject: Part of E.O. 12866 Review: Interagency Discussion about additional edits/materials for the MCA 

preamble pertaining to NESHAP: Mercury Emissions from Mercury Cell Chlor-Alkali Plants 2060-AN99

Hi Sharon,

Attached are redline comments on the mercury health effects section.

For the GHG benefits at 7%, see the example below from a recent DOE rule where they included the 

GHG benefits at 3% in the 7% number and there’s explanatory text in the preamble as well as a 

footnote. Let me know if you have any questions.

***

Preamble:

Using a 7-percent discount rate and the SCC value of $21.40/ton in 2010 (in 2007$), which is discounted 

at 3 percent (see note below in Table I.2), the cost of the standards proposed in today’s rule is $1,841 

million per year in increased equipment costs, while the annualized benefits are $2,112 million per year 

in reduced equipment operating costs, $316 million in CO2 reductions, and $7 million in reduced NOX 

emissions. In this case, the net benefit amounts to $594 million per year. Using a 3-percent discount rate 

and the SCC value of $21.40/ton in 2010 (in 2007$), the cost of the standards proposed in today’s rule is

$1,849 million per year in increased equipment costs, while the benefits are $2,929 million per year in 

reduced operating costs, $316 million in CO2 reductions, and $33 million in reduced NOX emissions. At a 

3-percent discount rate, the net benefit amounts to $1,429 million per year.

Table I.2. Annualized Benefits and Costs of Proposed Standards for Refrigeration Products for 2014-2043 

Period

Discount Rate Primary 

Estimate*

Low Estimate* High Estimate* 

Monetized (million 2009$/year)

Benefits 

Operating Cost Savings 7% 2112 1852 2377 

3% 2929 2520 3335 

CO2 Reduction at $4.7/t** 5% 85 85 85 

CO2 Reduction at $21.4/t** 3% 316 316 316 

CO2 Reduction at $35.1/t** 2.5% 492 492 492 

CO2 Reduction at $64.9/t** 3% 963 963 963 

NOX Reduction at $2,519/t** 7% 7 7 7 

3% 33 33 33 

Total (Operating Cost 

Savings, CO2 Reduction and 

NOx Reduction)† 

7% plus CO2 range 2204 - 3082 1944 - 2822 2469 - 3348 

7% 2435 2175 2700 

3% 3278 2869 3684 

3% plus CO2 range 3047 - 3925 2638 - 3516 3453 - 4331 

Costs 
Incremental Product Costs 7% 1841 1733 1950 

3% 1849 1729 1969 

Net Benefits/Costs 

Total (Operating Cost 

Savings, CO2 Reduction and 

NOx Reduction, minus 

Incremental Product Costs)† 

7% plus CO2 range 363 - 1241 211 - 1089 519 - 1397 

7% 594 442 750 

3% 1429 1140 1714 

3% plus CO2 range 1198 - 2076 909 - 1787 1483 - 2362 

* The Primary, Low, and High Estimates utilize forecasts of energy prices and housing starts from the 

AEO2010 Reference case, Low Economic Growth case, and Low Economic Growth case, respectively.

** The CO2 values represent global monetized values (in 2007$) of the social cost of CO2 emissions in 

2010 under several scenarios. The values of $4.70, $21.40, and $35.10 per ton are the averages of SCC 

distributions calculated using 5%, 3%, and 2.5% discount rates, respectively. The value of $64.90 per ton 

represents the 95th percentile of the SCC distribution calculated using a 3% discount rate. The value for 

NOX (in 2009$) is the average of the low and high values used in DOE’s analysis. NOx savings are in 

addition to the regulatory emissions reductions modeled in the Annual Energy Outlook forecast.

† Total Benefits for both the 3% and 7% cases are derived using the SCC value calculated at a 3% 

discount rate, which is $21.40/ton in 2010 (in 2007$). In the rows labeled as “7% plus CO2 range” and 

“3% plus CO2 range,” the operating cost and NOX benefits are calculated using the labeled discount 

rate, and those values are added to the full range of CO2 values with the $4.70/ton value at the low 

end, and the $64.90/ton value at the high end.

________________________________________________

Cortney Higgins, PhD

Policy Analyst

OMB/OIRA/NRE

202.395.7856

chiggins@omb.eop.gov

(See attached file: health effects-supplemental_EO12866comments.docx)
***E.O. 12866 Review – Draft – Do Not Cite, Quote, or Release During Review***

EO12866_Mercury Emissions from Mercury Cell Chlor-Alkali Plants 2060-AN99 NPRM MCA _20101122 

A. What are the effects of mercury?

Mercury is a naturally occurring element that is found in air, water, and soil in various 

forms. In general, industrial sources emit different combinations of three different forms (or 

species) of mercury to the atmosphere: gaseous elemental mercury (also know as elemental 

mercury vapor), gaseous inorganic mercury compounds (e.g., mercuric chloride), and 

particulate bound mercury. Mercury emissions from some industries are primarily in the form 

elemental mercury vapor (such as gold mine ore processing and production, and producers of 

blood pressure devices and fluorescent lighting). The majority of mercury emitted from 

mercury cell chlor-alkali plants is also in the form of elemental mercury vapor, with a small 

fraction (approximately 2 percent) being gaseous inorganic mercury. Other industries (such as 

coal-fired power plants and municipal waste combustion facilities) emit a combination of 

gaseous inorganic mercury and elemental mercury vapor and particulate bound mercury. The 

deposition of these emissions could, under circumstances described below, lead to formation of 

an organic form, methylmercury. 

In general, for elemental mercury, inhalation is the primary direct exposure route of 

potential concern. Effects on the nervous system appear to be the most sensitive toxicological 

endpoint and can include tremors, nervousness, insomnia, neuromuscular changes (such as 

weakness, muscle atrophy, and muscle twitching), headaches, polyneuropathy, and memory 

loss. Comment [A1]: What is the citation 

for this? We do not see these 

endpoints listed on the EPA webpage 

at 

http://www.epa.gov/mercury/effects.

htm
In general, for inorganic mercury compounds, both inhalation and ingestion exposure 

routes are of potential interest. Effects associated with high exposures to inorganic mercury 

compounds include damage to the gastrointestinal tract, the nervous system, and the kidneys. 

The most sensitive general systemic adverse effect due to exposure to inorganic mercury 

compounds is the formation of autoimmune glomerulonephritis (that is, inflammation of the 

kidney). Specific symptoms of high exposures to inorganic mercury can include skin rashes and 

dermatitis; mood swings; memory loss; mental disturbances; and muscle weakness. 

Mercury is emitted to the air from various man-made and 

natural sources. These emissions transport through the 

atmosphere and eventually deposit to land or water bodies. This 

deposition can occur locally, regionally, or globally, depending 

on the form of mercury emitted and other factors such as the 

weather. Gaseous elemental mercury can be transported very long 

distances, even globally, to regions far from the emissions 

source (becoming part of the global “pool”) before deposition 

occurs. Gaseous inorganic ionic (divalent) mercury has a 

shorter atmospheric lifetime and can deposit to land or water 

bodies closer to the emissions source. Furthermore, gaseous 

elemental mercury in the atmosphere can undergo transformation 

into ionic mercury, providing a significant pathway for 

deposition of emitted elemental mercury.

Once deposited, natural processes, particularly in water 

bodies, can transform some of the mercury into methylmercury, 

***E.O. 12866 Review – Draft – Do Not Cite, Quote, or Release During Review***

Comment [A2]: What is the citation 

for this?
which is a highly toxic, more bioavailable form that 

bioaccumulates in organisms and then biomagnifies in the aquatic 

food chain (such as in fish). Thus, the ingestion route via 

fish consumption dominates the pathway for human and wildlife 

exposure to methylmercury. Symptoms of methylmercury poisoning 

may include: impairment of the peripheral vision; disturbances 

in sensations; lack of coordination of movements; impairment of 

speech, hearing, walking; and muscle weakness. In general, 

while adults can experience effects from high ingestion exposure 

to methylmercury, exposures to developing fetuses, infants, and 

children can pose the highest concerns. For fetuses, infants, 

and children, the primary health effect of methylmercury is 

impaired neurological development. Methylmercury exposure in 

the womb can adversely affect a baby's growing brain and nervous 

system. Impacts on cognitive thinking, memory, attention, 

language, and fine motor and visual spatial skills have been 

seen in children exposed to methylmercury.

In general, avoidance of any potential for these health effects can result from reducing 

the amount of mercury released to the air, water, and other media. The four existing mercury 

cell chlor-alkali plants emit around 640 pounds of mercury each year to the air, based on recent 

estimates. They also release a total of just under 1 ton of mercury per year to other media, 

including around 50 pounds per year to water. The proposed amendments would result in the 

***E.O. 12866 Review – Draft – Do Not Cite, Quote, or Release During Review***

Comment [A3]: What is the citation 

for this?
elimination of these releases in the future, and therefore could have beneficial non-air quality 

health and environmental impacts.

In addition, mercury cell chlor-alkali plants are commonly identified as contaminated 

sites and designated for correction action under the EPA Superfund or Resource Conservation 

and Recovery Act (RCRA) corrective action programs. In fact, three of the four currently 

operating mercury cell plants have been identified under the RCRA corrective action program.

***E.O. 12866 Review – Draft – Do Not Cite, Quote, or Release During Review***

Comment [A4]: How commonly? Is there 

a percentage that can be given?